nebula 使用reversely 查询问题？

user84 · 2022 年11 月 25 日 10:24

提问参考模版：

nebula 版本：3.1.0
部署方式：分布式
安装方式：未知
是否为线上版本：N
硬件信息
- 磁盘未知
- CPU、内存信息未知

查询语句：

GO 1 to 100 steps FROM  "A" OVER follow  REVERSELY  
where properties(edge).deleted == 0  yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo

问题描述：A点->B点由于这条边的信息中携带一个deleted 字段用于判断暂时A点不指向B点，但是使用 REVERSELY 还是会返回结果B->A的数据？

caton-hpg · 2022 年11 月 25 日 11:03

A->B 这条边的 deleted 是1 ？

user84 · 2022 年11 月 25 日 11:15

是的，deleted 状态是1 但是REVERSELY 查询后还是查询出数据。

caton-hpg · 2022 年11 月 25 日 13:53

我试了下，是可以过滤的，你可能需要检查一下你的数据。

(root@nebula) [nba]> go 1 to 100 steps  from "Ray Allen" over * REVERSELY where properties(edge).likeness ==101 yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo
+-------+-------+----------+---------+---------+----------+
| srcId | dstId | edgeName | srcTags | dstTags | edgeInfo |
+-------+-------+----------+---------+---------+----------+
+-------+-------+----------+---------+---------+----------+
Empty set (time spent 271611/272192 us)

user84 · 2022 年11 月 28 日 04:01

可以使用以下数据进行查询
INSERT VERTEX player(name, age,deleted) VALUES “player100”:(“Tim Duncan”, 42,0);
INSERT VERTEX player(name, age,deleted) VALUES “player101”:(“Tony Parker”, 36,0);
INSERT VERTEX player(name, age,deleted) VALUES “player102”:(“LaMarcus Aldridge”, 33,0);

INSERT EDGE follow(degree,deleted) VALUES “player101” → “player100”:(95,0);
INSERT EDGE follow(degree,deleted) VALUES “player102” → “player101”:(96,0);

#此时去查没问题 player102->player101->player100
GO 1 to 100 steps FROM “player100” OVER follow REVERSELY where properties(edge).deleted == 0 yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo

#更新边为删除
UPDATE EDGE “player101” → “player100” OF follow SET deleted = 1;

#插入一个新点与新的边
INSERT VERTEX player(name, age,deleted) VALUES “player103”:(“Luka”, 23,0);

INSERT EDGE follow(degree,deleted) VALUES “player100” → “player103”:(95,0);

#再查询后会查询出 “player102” → “player101”
GO 1 to 100 steps FROM “player100” OVER follow REVERSELY where properties(edge).deleted == 0 yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo

按照个人理解是否"player102" → "player101"应该不显示，因为已经打断与player100 与 player101 之间的关系了？

min.wu · 2022 年11 月 28 日 10:01

哦哦。我猜测UPDATE EDGE这里有个bug。

可以从100 reversely 到101，返回下 edge.deleted.

user84 · 2022 年11 月 28 日 10:18

所以我该如何处理 “player102” → "player101"这种数据，因为查询的时候已经不会返回“player101” → “player100”的任何信息，edge.deleted.已经无法筛选

wey · 2022 年11 月 28 日 11:20

我似乎不能重现问题, GRAPHD 11.15 master; STORAGED 3.3.0

(root@nebula) [basketballplayer]> create space test0(partition_num=10,replica_factor=1,vid_type=fixed_string(32));
Execution succeeded (time spent 3795/14195 us)


(root@nebula) [basketballplayer]> use test0
Execution succeeded (time spent 1370/14198 us)

Mon, 28 Nov 2022 19:15:27 CST

(root@nebula) [test0]> create tag player(name string,age int, deleted int);
Execution succeeded (time spent 3901/10744 us)

Mon, 28 Nov 2022 19:15:35 CST

(root@nebula) [test0]> create tag team(name string);
Execution succeeded (time spent 3044/8084 us)

Mon, 28 Nov 2022 19:15:35 CST

(root@nebula) [test0]> create edge serve(start_year int,end_year int);
Execution succeeded (time spent 3108/8071 us)

Mon, 28 Nov 2022 19:15:35 CST

(root@nebula) [test0]> create edge follow(degree int, deleted int);
Execution succeeded (time spent 3487/16966 us)

Mon, 28 Nov 2022 19:15:35 CST

(root@nebula) [test0]> INSERT VERTEX player(name, age,deleted) VALUES "player100":("Tim Duncan", 42,0);
Execution succeeded (time spent 1829/10416 us)

Mon, 28 Nov 2022 19:15:44 CST

(root@nebula) [test0]> INSERT VERTEX player(name, age,deleted) VALUES "player101":("Tony Parker", 36,0);
Execution succeeded (time spent 1491/7126 us)

Mon, 28 Nov 2022 19:15:44 CST

(root@nebula) [test0]> INSERT VERTEX player(name, age,deleted) VALUES "player102":("LaMarcus Aldridge", 33,0);
Execution succeeded (time spent 1729/8454 us)

Mon, 28 Nov 2022 19:15:44 CST

(root@nebula) [test0]>
(root@nebula) [test0]> INSERT EDGE follow(degree,deleted) VALUES "player101" -> "player100":(95,0);
Execution succeeded (time spent 1388/7329 us)

Mon, 28 Nov 2022 19:15:44 CST

(root@nebula) [test0]> INSERT EDGE follow(degree,deleted) VALUES "player102" -> "player101":(96,0);
Execution succeeded (time spent 1468/7281 us)

Mon, 28 Nov 2022 19:15:44 CST

(root@nebula) [test0]>
(root@nebula) [test0]> GO 1 to 100 steps FROM "player100" OVER follow REVERSELY  where properties(edge).deleted == 0  yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| srcId       | dstId       | edgeName | srcTags                                                               | dstTags                                                         | edgeInfo                                                       |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| "player101" | "player100" | "follow" | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"})       | ("player100" :player{age: 42, deleted: 0, name: "Tim Duncan"})  | [:follow "player101"->"player100" @0 {degree: 95, deleted: 0}] |
| "player102" | "player101" | "follow" | ("player102" :player{age: 33, deleted: 0, name: "LaMarcus Aldridge"}) | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"}) | [:follow "player102"->"player101" @0 {degree: 96, deleted: 0}] |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
Got 2 rows (time spent 9908/20625 us)

Mon, 28 Nov 2022 19:15:53 CST

(root@nebula) [test0]> UPDATE EDGE "player101" -> "player100" OF follow SET deleted = 1;
Execution succeeded (time spent 3246/8908 us)

Mon, 28 Nov 2022 19:16:07 CST

(root@nebula) [test0]> INSERT VERTEX player(name, age,deleted) VALUES "player103":("Luka", 23,0);
Execution succeeded (time spent 1775/7270 us)

Mon, 28 Nov 2022 19:16:12 CST

(root@nebula) [test0]> INSERT EDGE follow(degree,deleted) VALUES "player100" -> "player103":(95,0);
Execution succeeded (time spent 1709/6850 us)

Mon, 28 Nov 2022 19:16:22 CST

## 可以看到 player101-player100 的被如期待过滤掉了

(root@nebula) [test0]> GO 1 to 100 steps FROM "player100" OVER follow REVERSELY  where properties(edge).deleted == 0  yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| srcId       | dstId       | edgeName | srcTags                                                               | dstTags                                                         | edgeInfo                                                       |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| "player102" | "player101" | "follow" | ("player102" :player{age: 33, deleted: 0, name: "LaMarcus Aldridge"}) | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"}) | [:follow "player102"->"player101" @0 {degree: 96, deleted: 0}] |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
Got 1 rows (time spent 10025/17533 us)

(root@nebula) [test0]> SHOW HOSTS GRAPH
+-----------+------+----------+---------+--------------+----------------------+
| Host      | Port | Status   | Role    | Git Info Sha | Version              |
+-----------+------+----------+---------+--------------+----------------------+
| "graphd"  | 9669 | "ONLINE" | "GRAPH" | "a5c08a6"    | "2022.11.15-nightly" |
| "graphd1" | 9669 | "ONLINE" | "GRAPH" | "c9f84b1"    | "3.3.0"              |
| "graphd2" | 9669 | "ONLINE" | "GRAPH" | "c9f84b1"    | "3.3.0"              |
+-----------+------+----------+---------+--------------+----------------------+
Got 3 rows (time spent 1678/15745 us)

Mon, 28 Nov 2022 19:19:52 CST

(root@nebula) [test0]> SHOW HOSTS storage
+-------------+------+----------+-----------+--------------+---------+
| Host        | Port | Status   | Role      | Git Info Sha | Version |
+-------------+------+----------+-----------+--------------+---------+
| "storaged0" | 9779 | "ONLINE" | "STORAGE" | "c9f84b1"    | "3.3.0" |
| "storaged1" | 9779 | "ONLINE" | "STORAGE" | "c9f84b1"    | "3.3.0" |
| "storaged2" | 9779 | "ONLINE" | "STORAGE" | "c9f84b1"    | "3.3.0" |
+-------------+------+----------+-----------+--------------+---------+
Got 3 rows (time spent 1631/13748 us)

wey · 2022 年11 月 28 日 11:24

你可以在新的数据上 100% 复现么？我怀疑是 edge partially write 了。

我感觉应该是很 rare 的 case，边写失败了，只成了一边（因为边是有两份的，一致性默认是不保证的）。

如果想保证边的一致性，开启 TOSS 这个开关是可以完全规避这个问题的，不过代价是性能，边数据更改时候会有锁。

user84 · 2022 年11 月 28 日 12:03

其实您已经复现出来了，只是我问题描述的点在于，我查询的是球员“player100”，REVERSELY的时候我不想看到数据"player102" ->“player101” 因为按照我的理解 “player101”->“player100” 已经被打断了。"player102"更不可能与"player100"发生联系

wey · 2022 年11 月 28 日 12:44

@caton-hpg 似乎这个目前 Filter 是在 GetNeighbors 之后 applied 的（而不是嵌在 GetNeighbors 里），所以实际上只应用在了最后一跳，这是期待中的语义么？还是说本质上是 https://github.com/vesoft-inc/nebula/issues/4573 ？

player101 -- player100 # deleted = 0
player102 -- player101

结果
player101 -- player100
player100--player102--player101

(root@nebula) [test0]> GO 1 to 100 steps FROM "player100" OVER follow REVERSELY  where properties(edge).deleted == 0  yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| srcId       | dstId       | edgeName | srcTags                                                               | dstTags                                                         | edgeInfo                                                       |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| "player101" | "player100" | "follow" | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"})       | ("player100" :player{age: 42, deleted: 0, name: "Tim Duncan"})  | [:follow "player101"->"player100" @0 {degree: 95, deleted: 0}] |
| "player102" | "player101" | "follow" | ("player102" :player{age: 33, deleted: 0, name: "LaMarcus Aldridge"}) | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"}) | [:follow "player102"->"player101" @0 {degree: 96, deleted: 0}] |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
Got 2 rows (time spent 9908/20625 us)

Mon, 28 Nov 2022 19:15:53 CST

player101 -- player100 # deleted = 1
player102 -- player101
player100 -- player103

结果
player100--player102--player101

(root@nebula) [test0]> GO 1 to 100 steps FROM "player100" OVER follow REVERSELY  where properties(edge).deleted == 0  yield src(edge) as srcId, dst(edge) as dstId,type(edge) as edgeName,$$ as srcTags,$^ as dstTags,edge as edgeInfo
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| srcId       | dstId       | edgeName | srcTags                                                               | dstTags                                                         | edgeInfo                                                       |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
| "player102" | "player101" | "follow" | ("player102" :player{age: 33, deleted: 0, name: "LaMarcus Aldridge"}) | ("player101" :player{age: 36, deleted: 0, name: "Tony Parker"}) | [:follow "player102"->"player101" @0 {degree: 96, deleted: 0}] |
+-------------+-------------+----------+-----------------------------------------------------------------------+-----------------------------------------------------------------+----------------------------------------------------------------+
Got 1 rows (time spent 10025/17533 us)

user84 · 2022 年12 月 1 日 09:04

目前这个需要怎么处理？

wey · 2022 年12 月 1 日 10:49

@MuYi GO 中的 WHERE 条件语义要改成最后一跳么？

min.wu · 2022 年12 月 2 日 08:47

这真是一个完全无法理解的奇怪行为。变成了实现决定行为。

user84 · 2022 年12 月 6 日 02:14

带入到真实场景举个例子朋友的朋友当切断朋友之间的关系当没有朋友的朋友直接联系方式时，不可能联系到朋友的朋友的吧？

min.wu · 2022 年12 月 6 日 05:53

这个是go中where的实现不太符合通常认知。已知该问题，但是否修复还没有计划。

user84 · 2022 年12 月 6 日 06:04

收到非常感谢您的回复。

system · 2023 年1 月 5 日 06:05

此话题已在最后回复的 30 天后被自动关闭。不再允许新回复。