记一次 rr 和硬件断点解决内存踩踏问题

在日常的调试过程中,我们总会遇到一些有趣的 bug,在本文我就遇到了一个有意思的查询结果不一致问题。

故事的开始

我们在测试 NebulaGraph 的 MATCH 语句的时候发现一个很神奇的事情:

(root@nebula) [gdlancer]> match (v1)-[e*1..1]->(v2) where id(v1) in [1, 2, 3, 4] and (v2)-[e*1..1]->(v1) return e;
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| e                                                                                                                                                                                       |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| [[:Rel_5 2->2 @0 {Rel_5_0_Bool: true, Rel_5_1_Bool: true, Rel_5_2_Double: 0.533698, Rel_5_3_String: "Stephen Curry", Rel_5_4_Double: 0.162998}]]                                        |
| [[:Rel_1 2->2 @0 {Rel_1_0_Int: 3, Rel_1_1_Int: 5, Rel_1_2_Int: 81, Rel_1_3_Double: 0.975062, Rel_1_4_Bool: true, Rel_1_5_Int: 59}]]                                                     |
| [[:Rel_0 2->2 @0 {Rel_0_0_Bool: true, Rel_0_1_String: "Kevin Durant", Rel_0_2_String: "Joel Embiid", Rel_0_3_Int: 96, Rel_0_4_Double: 0.468568, Rel_0_5_Int: 98, Rel_0_6_Int: 77}]]     |
| [[:Rel_2 2->2 @0 {Rel_2_0_Int: 38, Rel_2_1_Double: 0.120953, Rel_2_2_String: "Null1", Rel_2_3_Bool: false, Rel_2_4_Bool: true, Rel_2_5_Int: 6, Rel_2_6_String: "Tracy McGrady"}]]       |
| [[:Rel_3 2->2 @0 {Rel_3_0_String: "Aron Baynes", Rel_3_1_String: "LeBron James", Rel_3_2_Double: 0.831096, Rel_3_3_Int: 11}]]                                                           |
| [[:Rel_4 2->2 @0 {Rel_4_0_Bool: true, Rel_4_1_String: "Kevin Durant", Rel_4_2_Double: 0.71757, Rel_4_3_String: "Marc Gasol", Rel_4_4_Double: 0.285247, Rel_4_5_String: "Cory Joseph"}]] |
+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
Got 6 rows (time spent 146.7ms/168.31625ms)

Tue, 03 Jan 2023 14:10:03 CST

(root@nebula) [gdlancer]> match (v1)-[e*1..1]->(v2) where id(v1) in [1, 2, 3, 4] and (v2)-[e*1..1]->(v1) return e;
+---+
| e |
+---+
+---+
Empty set (time spent 30.67ms/58.220042ms)

Tue, 03 Jan 2023 14:10:05 CST

同样的语句,两次查询的结果集居然不一样!

开始 Debug

profile 出问题的语句:

(root@nebula) [gdlancer]> profile  match (v1)-[e*1..1]->(v2) where id(v1) in [1, 2, 3, 4] and (v2)-[e*1..1]->(v1) return e;
+---+
| e |
+---+
+---+
Empty set (time spent 18.755ms/79.84375ms)

Execution Plan (optimize time 1656 us)

-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
| id | name           | dependencies | profiling data                                       | operator info                                                             |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
| 12 | Project        | 11           | ver: 0, rows: 0, execTime: 17us, totalTime: 19us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "e"                                                                   |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__Project_12"                                                  |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __Filter_11                                                     |
|    |                |              |                                                      | columns: [                                                                |
|    |                |              |                                                      |   "$e"                                                                    |
|    |                |              |                                                      | ]                                                                         |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
| 11 | Filter         | 10           | ver: 0, rows: 0, execTime: 26us, totalTime: 29us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "v1",                                                                 |
|    |                |              |                                                      |     "e",                                                                  |
|    |                |              |                                                      |     "v2"                                                                  |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__Filter_11"                                                   |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __PatternApply_10                                               |
|    |                |              |                                                      | condition: ((id($v1)==1) OR (id($v1)==2) OR (id($v1)==3) OR (id($v1)==4)) |
|    |                |              |                                                      | isStable: false                                                           |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
| 10 | PatternApply   | 6,9          | ver: 0, rows: 0, execTime: 84us, totalTime: 87us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "v1",                                                                 |
|    |                |              |                                                      |     "e",                                                                  |
|    |                |              |                                                      |     "v2"                                                                  |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__PatternApply_10"                                             |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: {                                                               |
|    |                |              |                                                      |   "rightVar": "__AppendVertices_9",                                       |
|    |                |              |                                                      |   "leftVar": "__Project_6"                                                |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | keyCols: [                                                                |
|    |                |              |                                                      |   "id($-.v2)",                                                            |
|    |                |              |                                                      |   "id($-.v1)"                                                             |
|    |                |              |                                                      | ]                                                                         |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  6 | Project        | 5            | ver: 0, rows: 18, execTime: 103us, totalTime: 106us  | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "v1",                                                                 |
|    |                |              |                                                      |     "e",                                                                  |
|    |                |              |                                                      |     "v2"                                                                  |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "name": "__Project_6",                                                  |
|    |                |              |                                                      |   "type": "DATASET"                                                       |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __AppendVertices_5                                              |
|    |                |              |                                                      | columns: [                                                                |
|    |                |              |                                                      |   "$-.v1 AS v1",                                                          |
|    |                |              |                                                      |   "[__VAR_2 IN $-.e WHERE is_edge($__VAR_2)] AS e",                       |
|    |                |              |                                                      |   "$-.v2 AS v2"                                                           |
|    |                |              |                                                      | ]                                                                         |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  5 | AppendVertices | 4            | {                                                    | outputVar: {                                                              |
|    |                |              | ver: 0, rows: 18, execTime: 438us, totalTime: 1613us |   "colNames": [                                                           |
|    |                |              | resp[2]: {                                           |     "v1",                                                                 |
|    |                |              |   "exec": "308(us)",                                 |     "e",                                                                  |
|    |                |              |   "host": "store1:9779",                             |     "v2"                                                                  |
|    |                |              |   "total": "1114(us)"                                |   ],                                                                      |
|    |                |              | }                                                    |   "name": "__AppendVertices_5",                                           |
|    |                |              | total_rpc: 1350(us)                                  |   "type": "DATASET"                                                       |
|    |                |              | resp[0]: {                                           | }                                                                         |
|    |                |              |   "exec": "356(us)",                                 | inputVar: __Traverse_4                                                    |
|    |                |              |   "host": "store3:9779",                             | space: 8                                                                  |
|    |                |              |   "total": "1248(us)"                                | dedup: true                                                               |
|    |                |              | }                                                    | limit: -1                                                                 |
|    |                |              | resp[1]: {                                           | filter:                                                                   |
|    |                |              |   "exec": "323(us)",                                 | orderBy: []                                                               |
|    |                |              |   "host": "store2:9779",                             | src: none_direct_dst($-.e)                                                |
|    |                |              |   "total": "966(us)"                                 | props: [                                                                  |
|    |                |              | }                                                    |   {                                                                       |
|    |                |              | }                                                    |     "tagId": 13,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 12,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "tagId": 11                                                           |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 9,                                                           |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 10,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "tagId": 14                                                           |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "tagId": 15                                                           |
|    |                |              |                                                      |   }                                                                       |
|    |                |              |                                                      | ]                                                                         |
|    |                |              |                                                      | exprs:                                                                    |
|    |                |              |                                                      | vertex_filter:                                                            |
|    |                |              |                                                      | if_track_previous_path: true                                              |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  4 | Traverse       | 2            | {                                                    | outputVar: {                                                              |
|    |                |              | ver: 0, rows: 18, execTime: 597us, totalTime: 2943us |   "colNames": [                                                           |
|    |                |              | step[1]: [                                           |     "v1",                                                                 |
|    |                |              |   {                                                  |     "e"                                                                   |
|    |                |              |     "exec": "811(us)",                               |   ],                                                                      |
|    |                |              |     "host": "store2:9779",                           |   "name": "__Traverse_4",                                                 |
|    |                |              |     "storage_detail": {                              |   "type": "DATASET"                                                       |
|    |                |              |       "GetNeighborsNode": "551(us)",                 | }                                                                         |
|    |                |              |       "HashJoinNode": "415(us)",                     | inputVar: __Dedup_2                                                       |
|    |                |              |       "RelNode": "551(us)",                          | space: 8                                                                  |
|    |                |              |       "SingleEdgeNode": "391(us)"                    | dedup: true                                                               |
|    |                |              |     },                                               | limit: -1                                                                 |
|    |                |              |     "total": "2139(us)",                             | filter:                                                                   |
|    |                |              |     "total_rpc_time": "2328(us)",                    | orderBy: []                                                               |
|    |                |              |     "vertices": 2                                    | src: $-._vid                                                              |
|    |                |              |   },                                                 | edgeTypes: []                                                             |
|    |                |              |   {                                                  | edgeDirection: OUT_EDGE                                                   |
|    |                |              |     "exec": "769(us)",                               | vertexProps:                                                              |
|    |                |              |     "host": "store1:9779",                           | edgeProps: [                                                              |
|    |                |              |     "storage_detail": {                              |   {                                                                       |
|    |                |              |       "GetNeighborsNode": "259(us)",                 |     "type": 21,                                                           |
|    |                |              |       "HashJoinNode": "177(us)",                     |     "props": [                                                            |
|    |                |              |       "RelNode": "259(us)",                          |       "_src",                                                             |
|    |                |              |       "SingleEdgeNode": "161(us)"                    |       "_type",                                                            |
|    |                |              |     },                                               |       "_rank",                                                            |
|    |                |              |     "total": "1938(us)",                             |       "_dst",                                                             |
|    |                |              |     "total_rpc_time": "2328(us)",                    |       "Rel_5_0_Bool",                                                     |
|    |                |              |     "vertices": 1                                    |       "Rel_5_1_Bool",                                                     |
|    |                |              |   },                                                 |       "Rel_5_4_Double",                                                   |
|    |                |              |   {                                                  |       "Rel_5_3_String",                                                   |
|    |                |              |     "exec": "699(us)",                               |       "Rel_5_2_Double"                                                    |
|    |                |              |     "host": "store6:9779",                           |     ]                                                                     |
|    |                |              |     "storage_detail": {                              |   },                                                                      |
|    |                |              |       "GetNeighborsNode": "161(us)",                 |   {                                                                       |
|    |                |              |       "HashJoinNode": "152(us)",                     |     "props": [                                                            |
|    |                |              |       "RelNode": "162(us)",                          |       "_src",                                                             |
|    |                |              |       "SingleEdgeNode": "142(us)"                    |       "_type",                                                            |
|    |                |              |     },                                               |       "_rank",                                                            |
|    |                |              |     "total": "1735(us)",                             |       "_dst",                                                             |
|    |                |              |     "total_rpc_time": "2328(us)",                    |       "Rel_1_0_Int",                                                      |
|    |                |              |     "vertices": 1                                    |       "Rel_1_3_Double",                                                   |
|    |                |              |   }                                                  |       "Rel_1_2_Int",                                                      |
|    |                |              | ]                                                    |       "Rel_1_4_Bool",                                                     |
|    |                |              | }                                                    |       "Rel_1_5_Int",                                                      |
|    |                |              |                                                      |       "Rel_1_1_Int"                                                       |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "type": 17                                                            |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "type": 16,                                                           |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_src",                                                             |
|    |                |              |                                                      |       "_type",                                                            |
|    |                |              |                                                      |       "_rank",                                                            |
|    |                |              |                                                      |       "_dst",                                                             |
|    |                |              |                                                      |       "Rel_0_6_Int",                                                      |
|    |                |              |                                                      |       "Rel_0_0_Bool",                                                     |
|    |                |              |                                                      |       "Rel_0_3_Int",                                                      |
|    |                |              |                                                      |       "Rel_0_2_String",                                                   |
|    |                |              |                                                      |       "Rel_0_4_Double",                                                   |
|    |                |              |                                                      |       "Rel_0_1_String",                                                   |
|    |                |              |                                                      |       "Rel_0_5_Int"                                                       |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "type": 18,                                                           |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_src",                                                             |
|    |                |              |                                                      |       "_type",                                                            |
|    |                |              |                                                      |       "_rank",                                                            |
|    |                |              |                                                      |       "_dst",                                                             |
|    |                |              |                                                      |       "Rel_2_3_Bool",                                                     |
|    |                |              |                                                      |       "Rel_2_1_Double",                                                   |
|    |                |              |                                                      |       "Rel_2_4_Bool",                                                     |
|    |                |              |                                                      |       "Rel_2_5_Int",                                                      |
|    |                |              |                                                      |       "Rel_2_2_String",                                                   |
|    |                |              |                                                      |       "Rel_2_6_String",                                                   |
|    |                |              |                                                      |       "Rel_2_0_Int"                                                       |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "type": 19,                                                           |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_src",                                                             |
|    |                |              |                                                      |       "_type",                                                            |
|    |                |              |                                                      |       "_rank",                                                            |
|    |                |              |                                                      |       "_dst",                                                             |
|    |                |              |                                                      |       "Rel_3_0_String",                                                   |
|    |                |              |                                                      |       "Rel_3_3_Int",                                                      |
|    |                |              |                                                      |       "Rel_3_1_String",                                                   |
|    |                |              |                                                      |       "Rel_3_2_Double"                                                    |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_src",                                                             |
|    |                |              |                                                      |       "_type",                                                            |
|    |                |              |                                                      |       "_rank",                                                            |
|    |                |              |                                                      |       "_dst",                                                             |
|    |                |              |                                                      |       "Rel_4_0_Bool",                                                     |
|    |                |              |                                                      |       "Rel_4_2_Double",                                                   |
|    |                |              |                                                      |       "Rel_4_5_String",                                                   |
|    |                |              |                                                      |       "Rel_4_1_String",                                                   |
|    |                |              |                                                      |       "Rel_4_4_Double",                                                   |
|    |                |              |                                                      |       "Rel_4_3_String"                                                    |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "type": 20                                                            |
|    |                |              |                                                      |   }                                                                       |
|    |                |              |                                                      | ]                                                                         |
|    |                |              |                                                      | statProps:                                                                |
|    |                |              |                                                      | exprs:                                                                    |
|    |                |              |                                                      | random: false                                                             |
|    |                |              |                                                      | steps: 1..1                                                               |
|    |                |              |                                                      | vertex filter:                                                            |
|    |                |              |                                                      | edge filter:                                                              |
|    |                |              |                                                      | if_track_previous_path: false                                             |
|    |                |              |                                                      | first step filter:                                                        |
|    |                |              |                                                      | tag filter:                                                               |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  2 | Dedup          | 1            | ver: 0, rows: 4, execTime: 16us, totalTime: 18us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "_vid"                                                                |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__Dedup_2"                                                     |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __VAR_1                                                         |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  1 | PassThrough    | 3            | ver: 0, rows: 0, execTime: 14us, totalTime: 19us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "_vid"                                                                |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__VAR_1"                                                       |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar:                                                                 |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  3 | Start          |              | ver: 0, rows: 0, execTime: 2us, totalTime: 29us      | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [],                                                         |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__Start_3"                                                     |
|    |                |              |                                                      | }                                                                         |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  9 | AppendVertices | 8            | ver: 0, rows: 0, execTime: 46us, totalTime: 50us     | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "v2",                                                                 |
|    |                |              |                                                      |     "e",                                                                  |
|    |                |              |                                                      |     "v1"                                                                  |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__AppendVertices_9"                                            |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __Traverse_8                                                    |
|    |                |              |                                                      | space: 8                                                                  |
|    |                |              |                                                      | dedup: true                                                               |
|    |                |              |                                                      | limit: -1                                                                 |
|    |                |              |                                                      | filter:                                                                   |
|    |                |              |                                                      | orderBy: []                                                               |
|    |                |              |                                                      | src: none_direct_dst($-.e)                                                |
|    |                |              |                                                      | props: [                                                                  |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "tagId": 13                                                           |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ],                                                                    |
|    |                |              |                                                      |     "tagId": 12                                                           |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 11,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 9,                                                           |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 10,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 14,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   },                                                                      |
|    |                |              |                                                      |   {                                                                       |
|    |                |              |                                                      |     "tagId": 15,                                                          |
|    |                |              |                                                      |     "props": [                                                            |
|    |                |              |                                                      |       "_tag"                                                              |
|    |                |              |                                                      |     ]                                                                     |
|    |                |              |                                                      |   }                                                                       |
|    |                |              |                                                      | ]                                                                         |
|    |                |              |                                                      | exprs:                                                                    |
|    |                |              |                                                      | vertex_filter:                                                            |
|    |                |              |                                                      | if_track_previous_path: true                                              |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  8 | Traverse       | 7            | {                                                    | outputVar: {                                                              |
|    |                |              | ver: 0, rows: 0, execTime: 4867us, totalTime: 9173us |   "colNames": [                                                           |
|    |                |              | step[2]: [                                           |     "v2",                                                                 |
|    |                |              |   {                                                  |     "e"                                                                   |
|    |                |              |     "exec": "488(us)",                               |   ],                                                                      |
|    |                |              |     "host": "store2:9779",                           |   "type": "DATASET",                                                      |
|    |                |              |     "storage_detail": {                              |   "name": "__Traverse_8"                                                  |
|    |                |              |       "GetNeighborsNode": "371(us)",                 | }                                                                         |
|    |                |              |       "HashJoinNode": "261(us)",                     | inputVar: __Argument_7                                                    |
|    |                |              |       "RelNode": "371(us)",                          | space: 8                                                                  |
|    |                |              |       "SingleEdgeNode": "243(us)"                    | dedup: true                                                               |
|    |                |              |     },                                               | limit: -1                                                                 |
|    |                |              |     "total": "1509(us)",                             | filter:                                                                   |
|    |                |              |     "total_rpc_time": "1948(us)",                    | orderBy: []                                                               |
|    |                |              |     "vertices": 2                                    | src: id($-.v2)                                                            |
|    |                |              |   },                                                 | edgeTypes: []                                                             |
|    |                |              |   {                                                  | edgeDirection: OUT_EDGE                                                   |
|    |                |              |     "exec": "331(us)",                               | vertexProps:                                                              |
|    |                |              |     "host": "store3:9779",                           | edgeProps: [                                                              |
|    |                |              |     "storage_detail": {                              |   {                                                                       |
|    |                |              |       "GetNeighborsNode": "86(us)",                  |     "type": 21,                                                           |
|    |                |              |       "HashJoinNode": "63(us)",                      |     "props": [                                                            |
|    |                |              |       "RelNode": "86(us)",                           |       "_src",                                                             |
|    |                |              |       "SingleEdgeNode": "54(us)"                     |       "_type",                                                            |
|    |                |              |     },                                               |       "_rank",                                                            |
|    |                |              |     "total": "1208(us)",                             |       "_dst",                                                             |
|    |                |              |     "total_rpc_time": "1948(us)",                    |       "Rel_5_0_Bool",                                                     |
|    |                |              |     "vertices": 1                                    |       "Rel_5_1_Bool",                                                     |
|    |                |              |   },                                                 |       "Rel_5_4_Double",                                                   |
|    |                |              |   {                                                  |       "Rel_5_3_String",                                                   |
|    |                |              |     "exec": "686(us)",                               |       "Rel_5_2_Double"                                                    |
|    |                |              |     "host": "store5:9779",                           |     ]                                                                     |
|    |                |              |     "storage_detail": {                              |   },                                                                      |
|    |                |              |       "GetNeighborsNode": "311(us)",                 |   {                                                                       |
|    |                |              |       "HashJoinNode": "254(us)",                     |     "props": [                                                            |
|    |                |              |       "RelNode": "311(us)",                          |       "_src",                                                             |
|    |                |              |       "SingleEdgeNode": "237(us)"                    |       "_type",                                                            |
|    |                |              |     },                                               |       "_rank",                                                            |
|    |                |              |     "total": "1532(us)",                             |       "_dst",                                                             |
|    |                |              |     "total_rpc_time": "1948(us)",                    |       "Rel_1_0_Int",                                                      |
|    |                |              |     "vertices": 2                                    |       "Rel_1_3_Double",                                                   |
|    |                |              |   },                                                 |       "Rel_1_2_Int",                                                      |
|    |                |              |   {                                                  |       "Rel_1_4_Bool",                                                     |
|    |                |              |     "exec": "467(us)",                               |       "Rel_1_5_Int",                                                      |
|    |                |              |     "host": "store6:9779",                           |       "Rel_1_1_Int"                                                       |
|    |                |              |     "storage_detail": {                              |     ],                                                                    |
|    |                |              |       "GetNeighborsNode": "173(us)",                 |     "type": 17                                                            |
|    |                |              |       "HashJoinNode": "124(us)",                     |   },                                                                      |
|    |                |              |       "RelNode": "173(us)",                          |   {                                                                       |
|    |                |              |       "SingleEdgeNode": "115(us)"                    |     "type": 16,                                                           |
|    |                |              |     },                                               |     "props": [                                                            |
|    |                |              |     "total": "1368(us)",                             |       "_src",                                                             |
|    |                |              |     "total_rpc_time": "1948(us)",                    |       "_type",                                                            |
|    |                |              |     "vertices": 1                                    |       "_rank",                                                            |
|    |                |              |   },                                                 |       "_dst",                                                             |
|    |                |              |   {                                                  |       "Rel_0_6_Int",                                                      |
|    |                |              |     "exec": "494(us)",                               |       "Rel_0_0_Bool",                                                     |
|    |                |              |     "host": "store1:9779",                           |       "Rel_0_3_Int",                                                      |
|    |                |              |     "storage_detail": {                              |       "Rel_0_2_String",                                                   |
|    |                |              |       "GetNeighborsNode": "238(us)",                 |       "Rel_0_4_Double",                                                   |
|    |                |              |       "HashJoinNode": "147(us)",                     |       "Rel_0_1_String",                                                   |
|    |                |              |       "RelNode": "239(us)",                          |       "Rel_0_5_Int"                                                       |
|    |                |              |       "SingleEdgeNode": "137(us)"                    |     ]                                                                     |
|    |                |              |     },                                               |   },                                                                      |
|    |                |              |     "total": "1246(us)",                             |   {                                                                       |
|    |                |              |     "total_rpc_time": "1948(us)",                    |     "type": 18,                                                           |
|    |                |              |     "vertices": 1                                    |     "props": [                                                            |
|    |                |              |   }                                                  |       "_src",                                                             |
|    |                |              | ]                                                    |       "_type",                                                            |
|    |                |              | step[3]: [                                           |       "_rank",                                                            |
|    |                |              |   {                                                  |       "_dst",                                                             |
|    |                |              |     "exec": "643(us)",                               |       "Rel_2_3_Bool",                                                     |
|    |                |              |     "host": "store5:9779",                           |       "Rel_2_1_Double",                                                   |
|    |                |              |     "storage_detail": {                              |       "Rel_2_4_Bool",                                                     |
|    |                |              |       "GetNeighborsNode": "432(us)",                 |       "Rel_2_5_Int",                                                      |
|    |                |              |       "HashJoinNode": "296(us)",                     |       "Rel_2_2_String",                                                   |
|    |                |              |       "RelNode": "433(us)",                          |       "Rel_2_6_String",                                                   |
|    |                |              |       "SingleEdgeNode": "272(us)"                    |       "Rel_2_0_Int"                                                       |
|    |                |              |     },                                               |     ]                                                                     |
|    |                |              |     "total": "1556(us)",                             |   },                                                                      |
|    |                |              |     "total_rpc_time": "1913(us)",                    |   {                                                                       |
|    |                |              |     "vertices": 3                                    |     "type": 19,                                                           |
|    |                |              |   },                                                 |     "props": [                                                            |
|    |                |              |   {                                                  |       "_src",                                                             |
|    |                |              |     "exec": "581(us)",                               |       "_type",                                                            |
|    |                |              |     "host": "store6:9779",                           |       "_rank",                                                            |
|    |                |              |     "storage_detail": {                              |       "_dst",                                                             |
|    |                |              |       "GetNeighborsNode": "255(us)",                 |       "Rel_3_0_String",                                                   |
|    |                |              |       "HashJoinNode": "162(us)",                     |       "Rel_3_3_Int",                                                      |
|    |                |              |       "RelNode": "256(us)",                          |       "Rel_3_1_String",                                                   |
|    |                |              |       "SingleEdgeNode": "151(us)"                    |       "Rel_3_2_Double"                                                    |
|    |                |              |     },                                               |     ]                                                                     |
|    |                |              |     "total": "1612(us)",                             |   },                                                                      |
|    |                |              |     "total_rpc_time": "1913(us)",                    |   {                                                                       |
|    |                |              |     "vertices": 1                                    |     "type": 20,                                                           |
|    |                |              |   },                                                 |     "props": [                                                            |
|    |                |              |   {                                                  |       "_src",                                                             |
|    |                |              |     "exec": "373(us)",                               |       "_type",                                                            |
|    |                |              |     "host": "store2:9779",                           |       "_rank",                                                            |
|    |                |              |     "storage_detail": {                              |       "_dst",                                                             |
|    |                |              |       "GetNeighborsNode": "124(us)",                 |       "Rel_4_0_Bool",                                                     |
|    |                |              |       "HashJoinNode": "93(us)",                      |       "Rel_4_2_Double",                                                   |
|    |                |              |       "RelNode": "124(us)",                          |       "Rel_4_5_String",                                                   |
|    |                |              |       "SingleEdgeNode": "84(us)"                     |       "Rel_4_1_String",                                                   |
|    |                |              |     },                                               |       "Rel_4_4_Double",                                                   |
|    |                |              |     "total": "1285(us)",                             |       "Rel_4_3_String"                                                    |
|    |                |              |     "total_rpc_time": "1913(us)",                    |     ]                                                                     |
|    |                |              |     "vertices": 1                                    |   }                                                                       |
|    |                |              |   },                                                 | ]                                                                         |
|    |                |              |   {                                                  | statProps:                                                                |
|    |                |              |     "exec": "502(us)",                               | exprs:                                                                    |
|    |                |              |     "host": "store7:9779",                           | random: false                                                             |
|    |                |              |     "storage_detail": {                              | steps: 4..3                                                               |
|    |                |              |       "GetNeighborsNode": "157(us)",                 | vertex filter:                                                            |
|    |                |              |       "HashJoinNode": "132(us)",                     | edge filter:                                                              |
|    |                |              |       "RelNode": "157(us)",                          | if_track_previous_path: false                                             |
|    |                |              |       "SingleEdgeNode": "123(us)"                    | first step filter:                                                        |
|    |                |              |     },                                               | tag filter:                                                               |
|    |                |              |     "total": "1295(us)",                             |                                                                           |
|    |                |              |     "total_rpc_time": "1913(us)",                    |                                                                           |
|    |                |              |     "vertices": 1                                    |                                                                           |
|    |                |              |   }                                                  |                                                                           |
|    |                |              | ]                                                    |                                                                           |
|    |                |              | step[1]: [                                           |                                                                           |
|    |                |              |   {                                                  |                                                                           |
|    |                |              |     "exec": "522(us)",                               |                                                                           |
|    |                |              |     "host": "store3:9779",                           |                                                                           |
|    |                |              |     "storage_detail": {                              |                                                                           |
|    |                |              |       "GetNeighborsNode": "361(us)",                 |                                                                           |
|    |                |              |       "HashJoinNode": "272(us)",                     |                                                                           |
|    |                |              |       "RelNode": "361(us)",                          |                                                                           |
|    |                |              |       "SingleEdgeNode": "253(us)"                    |                                                                           |
|    |                |              |     },                                               |                                                                           |
|    |                |              |     "total": "1534(us)",                             |                                                                           |
|    |                |              |     "total_rpc_time": "1702(us)",                    |                                                                           |
|    |                |              |     "vertices": 2                                    |                                                                           |
|    |                |              |   },                                                 |                                                                           |
|    |                |              |   {                                                  |                                                                           |
|    |                |              |     "exec": "445(us)",                               |                                                                           |
|    |                |              |     "host": "store2:9779",                           |                                                                           |
|    |                |              |     "storage_detail": {                              |                                                                           |
|    |                |              |       "GetNeighborsNode": "185(us)",                 |                                                                           |
|    |                |              |       "HashJoinNode": "77(us)",                      |                                                                           |
|    |                |              |       "RelNode": "185(us)",                          |                                                                           |
|    |                |              |       "SingleEdgeNode": "69(us)"                     |                                                                           |
|    |                |              |     },                                               |                                                                           |
|    |                |              |     "total": "1296(us)",                             |                                                                           |
|    |                |              |     "total_rpc_time": "1702(us)",                    |                                                                           |
|    |                |              |     "vertices": 1                                    |                                                                           |
|    |                |              |   },                                                 |                                                                           |
|    |                |              |   {                                                  |                                                                           |
|    |                |              |     "exec": "529(us)",                               |                                                                           |
|    |                |              |     "host": "store1:9779",                           |                                                                           |
|    |                |              |     "storage_detail": {                              |                                                                           |
|    |                |              |       "GetNeighborsNode": "245(us)",                 |                                                                           |
|    |                |              |       "HashJoinNode": "155(us)",                     |                                                                           |
|    |                |              |       "RelNode": "245(us)",                          |                                                                           |
|    |                |              |       "SingleEdgeNode": "146(us)"                    |                                                                           |
|    |                |              |     },                                               |                                                                           |
|    |                |              |     "total": "1276(us)",                             |                                                                           |
|    |                |              |     "total_rpc_time": "1702(us)",                    |                                                                           |
|    |                |              |     "vertices": 1                                    |                                                                           |
|    |                |              |   }                                                  |                                                                           |
|    |                |              | ]                                                    |                                                                           |
|    |                |              | }                                                    |                                                                           |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------
|  7 | Argument       |              | ver: 0, rows: 4, execTime: 0us, totalTime: 55us      | outputVar: {                                                              |
|    |                |              |                                                      |   "colNames": [                                                           |
|    |                |              |                                                      |     "v2"                                                                  |
|    |                |              |                                                      |   ],                                                                      |
|    |                |              |                                                      |   "type": "DATASET",                                                      |
|    |                |              |                                                      |   "name": "__Argument_7"                                                  |
|    |                |              |                                                      | }                                                                         |
|    |                |              |                                                      | inputVar: __Project_6                                                     |
-----+----------------+--------------+------------------------------------------------------+----------------------------------------------------------------------------

Tue, 03 Jan 2023 15:54:06 CST

我们发现执行计划中编号 8 的节点对应的 step range 明显是错的:steps: 4…3(结合语句中的 e*1..1,正确值应该是 1..1)。

下面,我们通过 rr 录下一次错误的执行过程,然后在设置 MatchStepRange 的地方(src/graph/planner/match/MatchPathPlanner.cpp:282)下断点:

[New Thread 34.61]
[Switching to Thread 34.47]

Thread 3 hit Breakpoint 3, nebula::graph::MatchPathPlanner::rightExpandFromNode (this=0x18e60dc5c58, startIndex=0, subplan=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:282
282         traverse->setStepRange(edge.range);
(rr) bt
#0  nebula::graph::MatchPathPlanner::rightExpandFromNode (this=0x18e60dc5c58, startIndex=0, subplan=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:282
#1  0x00000000033198dd in nebula::graph::MatchPathPlanner::expandFromNode (this=0x18e60dc5c58, startIndex=0, subplan=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:169
#2  0x000000000331937b in nebula::graph::MatchPathPlanner::expand (this=0x18e60dc5c58, startFromEdge=false, startIndex=0, subplan=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:158
#3  0x00000000033185ca in nebula::graph::MatchPathPlanner::transform (this=0x18e60dc5c58, bindWhere=0x69433b909880, nodeAliasesSeen=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:78
#4  0x0000000003305b16 in nebula::graph::MatchClausePlanner::transform (this=0x69433bbd64b0, clauseCtx=0x7f25a94881c0) at /data/src/nebula-comm/src/graph/planner/match/MatchClausePlanner.cpp:33
#5  0x0000000003302a11 in nebula::graph::MatchPlanner::genPlan (this=0x69433b9998b0, clauseCtx=0x7f25a94881c0) at /data/src/nebula-comm/src/graph/planner/match/MatchPlanner.cpp:42
#6  0x0000000003303030 in nebula::graph::MatchPlanner::connectMatchPlan (this=0x69433b9998b0, queryPlan=..., matchCtx=0x7f25a94881c0) at /data/src/nebula-comm/src/graph/planner/match/MatchPlanner.cpp:63
#7  0x0000000003302101 in nebula::graph::MatchPlanner::genQueryPartPlan (this=0x69433b9998b0, qctx=0x7f25a94672a0, queryPlan=..., queryPart=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPlanner.cpp:137
#8  0x0000000003301e84 in nebula::graph::MatchPlanner::transform (this=0x69433b9998b0, astCtx=0x7f25a95eb700) at /data/src/nebula-comm/src/graph/planner/match/MatchPlanner.cpp:33
#9  0x00000000032e40b1 in nebula::graph::Planner::toPlan (astCtx=0x7f25a95eb700) at /data/src/nebula-comm/src/graph/planner/Planner.cpp:38
#10 0x00000000030d6b7e in nebula::graph::Validator::toPlan (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:401
#11 0x00000000030d5b93 in nebula::graph::Validator::validate (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:364
#12 0x0000000003114880 in nebula::graph::SequentialValidator::validateImpl (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/SequentialValidator.cpp:40
#13 0x00000000030d58e7 in nebula::graph::Validator::validate (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:354
#14 0x00000000030d4c8f in nebula::graph::Validator::validate (sentence=0x69433bc58870, qctx=0x7f25a94672a0) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:285
#15 0x0000000002ff4841 in nebula::graph::QueryInstance::validateAndOptimize (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:102
#16 0x0000000002ff3920 in nebula::graph::QueryInstance::execute (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:42
#17 0x0000000002fe9219 in nebula::graph::QueryEngine::execute (this=0x69433bc603c0, rctx=...) at /data/src/nebula-comm/src/graph/service/QueryEngine.cpp:57
#18 0x0000000002f6145f in nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1::operator()(nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >) (this=0x7f25a9452460, ret=...) at /data/src/nebula-comm/src/graph/service/GraphService.cpp:183
#19 0x0000000002f60626 in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}::operator()() const (this=0x18e60dc8120) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:98
#20 0x0000000002f605bf in folly::futures::detail::InvokeResultWrapper<void>::wrapResult<folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}>(folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}) (fn=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:90
#21 0x0000000002f6057c in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) (
    t=..., f=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:108
#22 0x0000000002f604cf in folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}::operator()(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&) (this=0x7f25a9452460, t=...)
    at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:991
#23 0x0000000002f6046e in folly::futures::detail::CoreCallbackState<folly::Unit, folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}>::invoke<folly::Executor::KeepAlive<folly::Executor>, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > > >(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&) (this=0x7f25a9452460, args=..., args=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:144
#24 0x0000000002f603cb in folly::futures::detail::detail_msvc_15_7_workaround::invoke<folly::futures::detail::tryExecutorCallableResult<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::alloc--Type <RET> for more, q to quit, c to continue without paging--q
Quit
(rr) p edge.range
$1 = (nebula::MatchStepRange *) 0x69433b948320
(rr) p *edge.range
$2 = {min_ = 1, max_ = 1}
(rr) c
Continuing.

Thread 3 hit Breakpoint 3, nebula::graph::MatchPathPlanner::rightExpandFromNode (this=0x18e60dc61f8, startIndex=0, subplan=...) at /data/src/nebula-comm/src/graph/planner/match/MatchPathPlanner.cpp:282
282         traverse->setStepRange(edge.range);
(rr) p edge.range
$3 = (nebula::MatchStepRange *) 0x69433b9998a0
(rr) p *edge.range
$4 = {min_ = 4, max_ = 3}
(rr) p &edge.range->min_
$5 = (size_t *) 0x69433b9998a0 (rr) watch *((size_t *) 0x69433b9998a0)
Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)
(rr)

我们发现第二次设置的 MatchStepRange(4..3) 显然已经出错。

我们在 &edge.range→min_ 这个地址(0x69433b9998a0)下个硬件断点,重新运行程序。

我们观察到 0x69433b9998a0 这个地址一直被反复的释放直到它被分配给一个 MatchStepRange 对象:

0x0000000003319f1d      282         traverse->setStepRange(edge.range);
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /root/src/nebula-comm/build-debug/bin/nebula-graphd

Program stopped.
0x00007f25a9200100 in ?? () from /lib64/ld-linux-x86-64.so.2
(rr) c
Continuing.
[New Thread 34.39]
[New Thread 34.35]
[New Thread 34.36]
[New Thread 34.37]
[New Thread 34.38]
[Switching to Thread 34.39]

Thread 2 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = <unreadable>
New value = 0
0x0000000070000002 in syscall_traced ()
(rr) c
Continuing.
[New Thread 34.56]
[New Thread 34.57]
[New Thread 34.40]
[New Thread 34.41]
[New Thread 34.42]
[New Thread 34.43]
[New Thread 34.44]
[New Thread 34.45]
[New Thread 34.46]
[New Thread 34.47]
[New Thread 34.48]
[New Thread 34.49]
[New Thread 34.50]
[New Thread 34.51]
[New Thread 34.52]
[New Thread 34.53]
[New Thread 34.54]
[New Thread 34.55]
[New Thread 34.58]
[New Thread 34.59]
[New Thread 34.60]
[New Thread 34.61]
[Switching to Thread 34.57]

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 0
New value = 128849018911
__memmove_avx_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:315
315     ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: No such file or directory.
(rr) c
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 128849018911
New value = 0
__memset_avx2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S:260
260     ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: No such file or directory.
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 0
New value = 139799731034544
std::_Hashtable<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, long>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, long> >, std::__detail::_Select1st, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<true, false, true> >::_M_insert_bucket_begin (this=0x7f25a94ed9a0, __bkt=0, __node=0x7f25a94e1a80)
    at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:1619
1619        {
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 139799731034544
New value = 0
__memset_avx2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S:260
260     ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: No such file or directory.
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 0
New value = 89457155694696
std::_Hashtable<int, std::pair<int const, std::vector<std::shared_ptr<nebula::meta::NebulaSchemaProvider const>, std::allocator<std::shared_ptr<nebula::meta::NebulaSchemaProvider const> > > >, std::allocator<std::pair<int const, std::vector<std::shared_ptr<nebula::meta::NebulaSchemaProvider const>, std::allocator<std::shared_ptr<nebula::meta::NebulaSchemaProvider const> > > > >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_insert_bucket_begin (this=0x515c5dfce058, __bkt=0, __node=0x69433bc58e70) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:1619
1619        {
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 89457155694696
New value = 115737483335024
0x0000000004066efa in std::_Hashtable<int, std::pair<int const, std::vector<std::shared_ptr<nebula::meta::NebulaSchemaProvider const>, std::allocator<std::shared_ptr<nebula::meta::NebulaSchemaProvider const> > > >, std::allocator<std::pair<int const, std::vector<std::shared_ptr<nebula::meta::NebulaSchemaProvider const>, std::allocator<std::shared_ptr<nebula::meta::NebulaSchemaProvider const> > > > >, std::__detail::_Select1st, std::equal_to<int>, std::hash<int>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, false, true> >::_M_insert_bucket_begin (this=0x515c5dfce058, __bkt=1, __node=0x69433b94d570) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:1616
1616                   _H1, _H2, _Hash, _RehashPolicy, _Traits>::
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 115737483335024
New value = 0
0x0000000003153d10 in std::__shared_ptr<nebula::meta::NebulaSchemaProvider const, (__gnu_cxx::_Lock_policy)2>::__shared_ptr (this=0x69433b9998a0) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/shared_ptr_base.h:1119
1119          : _M_ptr(0), _M_refcount()
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 0
New value = 139799732183408
std::swap<nebula::meta::NebulaSchemaProvider const*> (__a=@0x515c5dfcd878: 0x0, __b=@0x69433b9998a0: 0x7f25a9606170) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/move.h:196
196         }
(rr)
Continuing.

Thread 8 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 139799732183408
New value = 0
__memset_avx2_unaligned_erms () at ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S:260
260     ../sysdeps/x86_64/multiarch/memset-vec-unaligned-erms.S: No such file or directory.
(rr)
Continuing.
[Switching to Thread 34.47]

Thread 16 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 0
New value = 98202129293344
__memmove_avx_unaligned_erms () at ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S:315
315     ../sysdeps/x86_64/multiarch/memmove-vec-unaligned-erms.S: No such file or directory.
(rr)
Continuing.

Thread 16 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 98202129293344
New value = 1
0x00000000031e675d in std::make_unique<nebula::MatchStepRange, nebula::MatchStepRange&> (__args=...) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/unique_ptr.h:857
857         { return unique_ptr<_Tp>(new _Tp(std::forward<_Args>(__args)...)); }
(rr) bt
#0  0x00000000031e675d in std::make_unique<nebula::MatchStepRange, nebula::MatchStepRange&> (__args=...) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/unique_ptr.h:857
#1  0x00000000031e586a in nebula::MatchEdge::clone (this=0x69433b919530) at /data/src/nebula-comm/src/parser/MatchPath.h:128
#2  0x00000000031e082d in nebula::MatchPath::clone (this=0x7f25a94d3b00) at /data/src/nebula-comm/src/parser/MatchPath.h:363
#3  0x00000000031e0161 in nebula::graph::extractSinglePathPredicate (expr=0x595077086880, pathPreds=...) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:1122
#4  0x00000000031e0b43 in nebula::graph::extractMultiPathPredicate (expr=0x595077085e60, pathPreds=...) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:1158
#5  0x00000000031d87aa in nebula::graph::MatchValidator::validatePathInWhere (this=0x69433bbd0f80, wctx=..., availableAliases=..., paths=...) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:1182
#6  0x00000000031cfddc in nebula::graph::MatchValidator::validateFilter (this=0x69433bbd0f80, filter=0x595077006eb0, whereClauseCtx=...) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:361
#7  0x00000000031cdd60 in nebula::graph::MatchValidator::validateImpl (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:66
#8  0x00000000030d58e7 in nebula::graph::Validator::validate (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:354
#9  0x0000000003114880 in nebula::graph::SequentialValidator::validateImpl (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/SequentialValidator.cpp:40
#10 0x00000000030d58e7 in nebula::graph::Validator::validate (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:354
#11 0x00000000030d4c8f in nebula::graph::Validator::validate (sentence=0x69433bc58870, qctx=0x7f25a94672a0) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:285
#12 0x0000000002ff4841 in nebula::graph::QueryInstance::validateAndOptimize (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:102
#13 0x0000000002ff3920 in nebula::graph::QueryInstance::execute (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:42
#14 0x0000000002fe9219 in nebula::graph::QueryEngine::execute (this=0x69433bc603c0, rctx=...) at /data/src/nebula-comm/src/graph/service/QueryEngine.cpp:57
#15 0x0000000002f6145f in nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1::operator()(nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >) (this=0x7f25a9452460, ret=...) at /data/src/nebula-comm/src/graph/service/GraphService.cpp:183
#16 0x0000000002f60626 in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}::operator()() const (this=0x18e60dc8120) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:98
#17 0x0000000002f605bf in folly::futures::detail::InvokeResultWrapper<void>::wrapResult<folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}>(folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}) (fn=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:90
#18 0x0000000002f6057c in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) (
    t=..., f=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:108
#19 0x0000000002f604cf in folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}::operator()(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&) (this=0x7f25a9452460, t=...)
    at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:991
#20 0x0000000002f6046e in folly::futures::detail::CoreCallbackState<folly::Unit, folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}>::invoke<folly::Executor::KeepAlive<folly::Executor>, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > > >(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&) (this=0x7f25a9452460, args=..., args=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:144
#21 0x0000000002f603cb in folly::futures::detail::detail_msvc_15_7_workaround::invoke<folly::futures::detail::tryExecutorCallableResult<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}, void>, folly::futures::detail::CoreCallbackState<folly::Unit, {lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}>, nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, 0>(folly::futures::detail::tryExecutorCallableResult<nebula::StatusOr<
--Type <RET> for more, q to quit, c to continue without paging--q
Quit
(rr)

可以看到出问题的 MatchStepRangesrc/parser/MatchPath.h:128 通过 make_unique 分配出的内存并初始化的:

119
120   MatchEdge clone() const {
121     auto me = MatchEdge();
122     me.direction_ = direction_;
123     me.alias_ = alias_;
124     for (const auto& type : types_) {
125       me.types_.emplace_back(std::make_unique<std::string>(*DCHECK_NOTNULL(type)));
126     }
127     if (range_ != nullptr) {
128       me.range_ = std::make_unique<MatchStepRange>(*range_);
129     }
130     if (props_ != nullptr) {
131       me.props_ = static_cast<MapExpression*>(props_->clone());
132     }
133     return me;
134   }
135
136  private:
137   Direction direction_;
138   std::string alias_;

继续 continue 看这块内存上的数据什么时候被篡改成错误的值:

Continuing.

Thread 16 hit Hardware watchpoint 4: *((size_t *) 0x69433b9998a0)

Old value = 1
New value = 0
0x0000000002ec2901 in std::__detail::_Hash_node_base::_Hash_node_base (this=0x69433b9998a0) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:218
218         _Hash_node_base() noexcept : _M_nxt() { }
(rr) bt
#0  0x0000000002ec2901 in std::__detail::_Hash_node_base::_Hash_node_base (this=0x69433b9998a0) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:218
#1  0x0000000002ed1191 in std::__detail::_Hash_node_value_base<nebula::Expression::Kind>::_Hash_node_value_base (this=0x69433b9998a0) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:229
#2  0x0000000002ed10c1 in std::__detail::_Hash_node<nebula::Expression::Kind, false>::_Hash_node (this=0x69433b9998a0) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:279
#3  0x0000000002ed0f9b in std::__detail::_Hashtable_alloc<std::allocator<std::__detail::_Hash_node<nebula::Expression::Kind, false> > >::_M_allocate_node<nebula::Expression::Kind const&> (this=0x18e60dc63b8, __args=@0x18e60dc63a6: nebula::Expression::Kind::kVertex)
    at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:2085
#4  0x0000000002ed0cf3 in std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<nebula::Expression::Kind, false> > >::operator()<nebula::Expression::Kind const&> (this=0x18e60dc5ef8, __arg=@0x18e60dc63a6: nebula::Expression::Kind::kVertex)
    at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:167
#5  0x0000000002ed0bc2 in std::_Hashtable<nebula::Expression::Kind, nebula::Expression::Kind, std::allocator<nebula::Expression::Kind>, std::__detail::_Identity, std::equal_to<nebula::Expression::Kind>, std::hash<nebula::Expression::Kind>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, true, true> >::_M_insert<nebula::Expression::Kind const&, std::__detail::_AllocNode<std::allocator<std::__detail::_Hash_node<nebula::Expression::Kind, false> > > > (
    this=0x18e60dc63b8, __v=@0x18e60dc63a6: nebula::Expression::Kind::kVertex, __node_gen=..., __n_elt=1) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:1852
#6  0x0000000002ed06cd in std::__detail::_Insert_base<nebula::Expression::Kind, nebula::Expression::Kind, std::allocator<nebula::Expression::Kind>, std::__detail::_Identity, std::equal_to<nebula::Expression::Kind>, std::hash<nebula::Expression::Kind>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, true, true> >::insert (this=0x18e60dc63b8, __v=@0x18e60dc63a6: nebula::Expression::Kind::kVertex)
    at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable_policy.h:824
#7  0x0000000002ed042d in std::_Hashtable<nebula::Expression::Kind, nebula::Expression::Kind, std::allocator<nebula::Expression::Kind>, std::__detail::_Identity, std::equal_to<nebula::Expression::Kind>, std::hash<nebula::Expression::Kind>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, true, true> >::_Hashtable<nebula::Expression::Kind const*> (this=0x18e60dc63b8, __f=0x18e60dc63a6, __l=0x18e60dc63a8, __bucket_hint=0, __h1=..., __h2=..., __h=..., __eq=...,
    __exk=..., __a=...) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:1026
#8  0x0000000002ed01bc in std::_Hashtable<nebula::Expression::Kind, nebula::Expression::Kind, std::allocator<nebula::Expression::Kind>, std::__detail::_Identity, std::equal_to<nebula::Expression::Kind>, std::hash<nebula::Expression::Kind>, std::__detail::_Mod_range_hashing, std::__detail::_Default_ranged_hash, std::__detail::_Prime_rehash_policy, std::__detail::_Hashtable_traits<false, true, true> >::_Hashtable (this=0x18e60dc63b8, __l=..., __n=0, __hf=..., __eql=..., __a=...) at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/hashtable.h:497
#9  0x0000000002eae859 in std::unordered_set<nebula::Expression::Kind, std::hash<nebula::Expression::Kind>, std::equal_to<nebula::Expression::Kind>, std::allocator<nebula::Expression::Kind> >::unordered_set (this=0x18e60dc63b8, __l=..., __n=0, __hf=..., __eql=..., __a=...)
    at /usr/lib/gcc/x86_64-linux-gnu/9/../../../../include/c++/9/bits/unordered_set.h:226
#10 0x00000000031d2df0 in nebula::graph::MatchValidator::validateReturn (this=0x69433bbd0f80, ret=0x69433bc587b0, queryParts=..., retClauseCtx=...) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:471
#11 0x00000000031ce962 in nebula::graph::MatchValidator::validateImpl (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/MatchValidator.cpp:117
#12 0x00000000030d58e7 in nebula::graph::Validator::validate (this=0x69433bbd0f80) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:354
#13 0x0000000003114880 in nebula::graph::SequentialValidator::validateImpl (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/SequentialValidator.cpp:40
#14 0x00000000030d58e7 in nebula::graph::Validator::validate (this=0x69433bbd0c00) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:354
#15 0x00000000030d4c8f in nebula::graph::Validator::validate (sentence=0x69433bc58870, qctx=0x7f25a94672a0) at /data/src/nebula-comm/src/graph/validator/Validator.cpp:285
#16 0x0000000002ff4841 in nebula::graph::QueryInstance::validateAndOptimize (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:102
#17 0x0000000002ff3920 in nebula::graph::QueryInstance::execute (this=0x69433bc07640) at /data/src/nebula-comm/src/graph/service/QueryInstance.cpp:42
#18 0x0000000002fe9219 in nebula::graph::QueryEngine::execute (this=0x69433bc603c0, rctx=...) at /data/src/nebula-comm/src/graph/service/QueryEngine.cpp:57
#19 0x0000000002f6145f in nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1::operator()(nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >) (this=0x7f25a9452460, ret=...) at /data/src/nebula-comm/src/graph/service/GraphService.cpp:183
#20 0x0000000002f60626 in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}::operator()() const (this=0x18e60dc8120) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:98
#21 0x0000000002f605bf in folly::futures::detail::InvokeResultWrapper<void>::wrapResult<folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}>(folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&)::{lambda()#1}) (fn=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:90
#22 0x0000000002f6057c in folly::futures::detail::wrapInvoke<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> >, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&, nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) (
    t=..., f=...) at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:108
#23 0x0000000002f604cf in folly::Future<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >::thenValue<nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1>(nebula::graph::GraphService::future_executeWithParameter(long, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::unordered_map<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, nebula::Value, std::hash<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::equal_to<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const, nebula::Value> > > const&)::$_1&&) &&::{lambda(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&)#1}::operator()(folly::Executor::KeepAlive<folly::Executor>&&, folly::Try<nebula::StatusOr<std::shared_ptr<nebula::graph::ClientSession> > >&&) (this=0x7f25a9452460, t=...)
    at /data/src/nebula-comm/build-debug/third-party/install/include/folly/futures/Future-inl.h:991
--Type <RET> for more, q to quit, c to continue without paging--q
Quit
(rr)

非常神奇的是,这块内存在 src/graph/validator/MatchValidator.cpp:471 中又分配给某个 hash 表了:

 449 // Check validity of return clause.
 450 // Disable return * without symbols, disable invalid expressions, check aggregate expression,
 451 // rewrite expression to fit semantic, check available aliases, check columns, check limit and
 452 // order by options.
 453 Status MatchValidator::validateReturn(MatchReturn *ret,
 454                                       const std::vector<QueryPart> &queryParts,
 455                                       ReturnClauseContext &retClauseCtx) {
 456   YieldColumns *columns = retClauseCtx.qctx->objPool()->makeAndAdd<YieldColumns>();
 457   if (ret->returnItems()->allNamedAliases() && !queryParts.empty()) {
 458     auto status = buildColumnsForAllNamedAliases(queryParts, columns);
 459     if (!status.ok()) {
 460       return status;
 461     }
 462     if (columns->empty() && !ret->returnItems()->columns()) {
 463       return Status::SemanticError("RETURN * is not allowed when there are no variables in scope");
 464     }
 465   }
 466   std::vector<const Expression *> exprs;
 467   if (ret->returnItems()->columns()) {
 468     exprs.reserve(ret->returnItems()->columns()->size());
 469     for (auto *column : ret->returnItems()->columns()->columns()) {
 470       if (ExpressionUtils::hasAny(column->expr(),
 471                                   {Expression::Kind::kVertex, Expression::Kind::kEdge})) {
 472         return Status::SemanticError(
 473             "keywords: vertex and edge are not supported in return clause `%s'",
 474             column->toString().c_str());
 475       }
 476       if (!retClauseCtx.yield->hasAgg_ &&
 477           ExpressionUtils::hasAny(column->expr(), {Expression::Kind::kAggregate})) {
 478         retClauseCtx.yield->hasAgg_ = true;
 479       }
 480       column->setExpr(ExpressionUtils::rewriteAttr2LabelTagProp(
 481           column->expr(), retClauseCtx.yield->aliasesAvailable));
 482       exprs.push_back(column->expr());
 483       columns->addColumn(column->clone().release());
 484     }
 485   }

唯一的解释就是 MatchStepRange 所在的内存被释放然后又分配出去了。重点关注 MatchStepRange 内存的分配、释放过程,我们顺着 make_unique() 分配 MatchStepRange 的堆栈跟过去:

1171
1172 Status MatchValidator::validatePathInWhere(
1173     WhereClauseContext &wctx,
1174     const std::unordered_map<std::string, AliasType> &availableAliases,
1175     std::vector<Path> &paths) {
1176   auto expr = ExpressionUtils::flattenInnerLogicalExpr(wctx.filter);
1177   auto *pool = qctx_->objPool();
1178   ValidatePatternExpressionVisitor visitor(pool, vctx_);
1179   expr->accept(&visitor);
1180   std::vector<MatchPath> pathPreds;
1181   // FIXME(czp): Delete this function and add new expression visitor to cover all general cases
1182   if (extractMultiPathPredicate(expr, pathPreds)) {
1183     wctx.filter = nullptr;
1184   } else {
1185     // Flatten and fold the inner logical expressions that already have operands that can be
1186     // compacted
1187     wctx.filter =
1188         ExpressionUtils::foldInnerLogicalExpr(ExpressionUtils::flattenInnerLogicalExpr(expr));
1189   }
1190   for (auto &pred : pathPreds) {
1191     NG_RETURN_IF_ERROR(checkMatchPathExpr(pred, availableAliases));
1192     // Build path alias
1193     auto pathAlias = pred.toString();
1194     pred.setAlias(new std::string(pathAlias));
1195     paths.emplace_back();
1196     NG_RETURN_IF_ERROR(validatePath(&pred, paths.back()));
1197     NG_RETURN_IF_ERROR(buildRollUpPathInfo(&pred, paths.back()));
1198   }

MatchStepRangegraph/validator/MatchValidator.cpp:1182 这行代码触发分配的,保存在 pathPreds 这个 vector 中。在 NebulaGraph 中不定长(变长)查询 :<edge_type>*[minHop..maxHop] 会触发 extractMultiPathPredicate() 函数来分配 match path range,本文就是触发了 extractMultiPathPredicate() 函数。

回到上面代码,这里就有个问题:pathPreds 是个局部变量,validatePathInWhere() 一旦执行结束它的内存就释放了,这当然包括 MatchStepRange 这个 unique_ptr。再看 MatchStepRange 这块内存是否在释放后还被其他地方被用到。查看代码我们发现 graph/validator/MatchValidator.cpp:1196 这行代码的产生的调用链 validatePath()-> buildEdgeInfo()pred 中的 MatchStepRange 裸指针赋值出去了:

 138 // Validate pattern from expression
 139 Status MatchValidator::validatePath(const MatchPath *path, Path &pathInfo) {
 140   // Pattern from expression won't generate new variable
 141   std::unordered_map<std::string, AliasType> dummy;
 142   NG_RETURN_IF_ERROR(buildNodeInfo(path, pathInfo.nodeInfos, dummy));
 143   NG_RETURN_IF_ERROR(buildEdgeInfo(path, pathInfo.edgeInfos, dummy));
 144   NG_RETURN_IF_ERROR(buildPathExpr(path, pathInfo, dummy));
 145   pathInfo.isPred = path->isPredicate();
 146   pathInfo.isAntiPred = path->isAntiPredicate();
 147
 148   return Status::OK();
 149 }
...
 263 // Build edges information by match pattern.
 264 Status MatchValidator::buildEdgeInfo(const MatchPath *path,
 265                                      std::vector<EdgeInfo> &edgeInfos,
 266                                      std::unordered_map<std::string, AliasType> &aliases) {
 267   auto *sm = qctx_->schemaMng();
 268   auto steps = path->steps();
 269   edgeInfos.resize(steps);
 270
 271   for (auto i = 0u; i < steps; i++) {
 272     auto *edge = path->edge(i);
 273     auto &types = edge->types();
...
 298     AliasType aliasType = AliasType::kEdge;
 299     auto *stepRange = edge->range();
 300     if (stepRange != nullptr) {
 301       NG_RETURN_IF_ERROR(validateStepRange(stepRange));
 302       edgeInfos[i].range = stepRange;

src/graph/validator/MatchValidator.cpp:299,直接赋值了那块即将被释放的 MatchStepRange 指针,这是一切悲剧的根源。

问题定位到了,也就好解决了。


谢谢你读完本文 (///▽///)

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