nebula-go 3.4.0 query nothing from nebula server 3.4.1

[supermario1990]

I updated nebula server from 3.2.0 to 3.4.1, when I use nebula-go client(3.4.0), I can not query anything. while when I use python client(3.4.0), I can query the right results

[wey-gu]

Could you provide how this "can not query anything" looks like? I guess something is wrong.

The nebula-console is based on nebula-go, you should verify quite easily actually that 3.4.0 works fine.

Thanks!

[supermario1990]

Could you provide how this "can not query anything" looks like? I guess something is wrong.

The nebula-console is based on nebula-go, you should verify quite easily actually that 3.4.0 works fine.

Thanks!

thanks for reply. I will supply my code snippet to reproduce the problem.

[supermario1990]

my nebula server info:

root@VM-16-10-ubuntu:~/download# /usr/local/nebula/scripts/nebula.service status all
[INFO] nebula-metad(a6dc673): Running as 7384, Listening on 9559
[INFO] nebula-graphd(a6dc673): Running as 7494, Listening on 9669
[INFO] nebula-storaged(a6dc673): Running as 7548, Listening on 9779
root@VM-16-10-ubuntu:~/download# 
root@VM-16-10-ubuntu:~/download# 
root@VM-16-10-ubuntu:~/download# /usr/local/nebula/bin/nebula-graphd -version
nebula-graphd version 3.4.1, Git: a6dc673, Build Time: Mar  6 2023 18:40:11
This source code is licensed under Apache 2.0 License.

[supermario1990]

go code:

/*
 
 * Copyright (c) 2021 vesoft inc. All rights reserved.
 *
 * This source code is licensed under Apache 2.0 License.
 *
 */

package main

import (
	"fmt"

	nebula "github.com/vesoft-inc/nebula-go/v3"
)

const (
	address = "124.222.227.15"
	// The default port of NebulaGraph 2.x is 9669.
	// 3699 is only for testing.
	port     = 9669
	username = "root"
	password = "nebula"
)

// Initialize logger
var log = nebula.DefaultLogger{}

func main() {
	hostAddress := nebula.HostAddress{Host: address, Port: port}
	hostList := []nebula.HostAddress{hostAddress}
	// Create configs for connection pool using default values
	testPoolConfig := nebula.GetDefaultConf()

	// Initialize connection pool
	pool, err := nebula.NewConnectionPool(hostList, testPoolConfig, log)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to initialize the connection pool, host: %s, port: %d, %s", address, port, err.Error()))
	}
	// Close all connections in the pool
	defer pool.Close()

	// Create session
	session, err := pool.GetSession(username, password)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to create a new session from connection pool, username: %s, password: %s, %s",
			username, password, err.Error()))
	}
	// Release session and return connection back to connection pool
	defer session.Release()

	{
		// Prepare the query
		sql := `use manager;MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc 
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*0]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass;`

		// Execute a query
		resultSet, err := session.Execute(sql)
		if err != nil {
			fmt.Print(err.Error())
			return
		}
		fmt.Println(resultSet)
		for _, v := range resultSet.GetRows() {
			fmt.Println(string(v.GetValues()[0].SVal))
			fmt.Println(string(v.GetValues()[1].SVal))
			fmt.Println(string(v.GetValues()[2].SVal))
			fmt.Println(string(v.GetValues()[3].SVal))
			fmt.Println(string(v.GetValues()[4].SVal))
		}
	}

	fmt.Print("\n")
	log.Info("Nebula Go Client Basic Example Finished")
}

output:

&{0xc0000e60e0 [id name batchno process pass] map[batchno:2 id:0 name:1 pass:4 process:3] {0 [85 84 67]}}

[supermario1990]

python code:

from nebula3.gclient.net import ConnectionPool
from nebula3.Config import Config

# define a config
config = Config()
config.max_connection_pool_size = 10
# init connection pool
connection_pool = ConnectionPool()
# if the given servers are ok, return true, else return false
ok = connection_pool.init([('124.222.227.15', 9669)], config)

# option 1 control the connection release yourself
# get session from the pool
session = connection_pool.get_session('root', 'nebula')

# select space
session.execute('USE manager')

# show tags
result = session.execute('''
MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc 
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*0]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass;
''')
print(result)

# release session
session.release()

# close the pool
connection_pool.close()

output:

ResultSet(keys: ['id', 'name', 'batchno', 'process', 'pass'], values: [52, "成品批号", "BF14CDZ1-210107A1-02", "粉碎", "1"])

[supermario1990]

just run the code upper, the server in the code is available.
go client and python client are all 3.4.0 @wey-gu

[supermario1990]

in addition， when i downgrade nebula server to 3.2.0, the go client can query the right results.

[wey-gu]

Allow me to ping @Aiee for taking a look at it.
thanks

[supermario1990]

go code:

/*
 
 * Copyright (c) 2021 vesoft inc. All rights reserved.
 *
 * This source code is licensed under Apache 2.0 License.
 *
 */

package main

import (
	"fmt"

	nebula "github.com/vesoft-inc/nebula-go/v3"
)

const (
	address = "124.222.227.15"
	// The default port of NebulaGraph 2.x is 9669.
	// 3699 is only for testing.
	port     = 9669
	username = "root"
	password = "nebula"
)

// Initialize logger
var log = nebula.DefaultLogger{}

func main() {
	hostAddress := nebula.HostAddress{Host: address, Port: port}
	hostList := []nebula.HostAddress{hostAddress}
	// Create configs for connection pool using default values
	testPoolConfig := nebula.GetDefaultConf()

	// Initialize connection pool
	pool, err := nebula.NewConnectionPool(hostList, testPoolConfig, log)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to initialize the connection pool, host: %s, port: %d, %s", address, port, err.Error()))
	}
	// Close all connections in the pool
	defer pool.Close()

	// Create session
	session, err := pool.GetSession(username, password)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to create a new session from connection pool, username: %s, password: %s, %s",
			username, password, err.Error()))
	}
	// Release session and return connection back to connection pool
	defer session.Release()

	{
		// Prepare the query
		sql := `use manager;MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc 
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*0]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass;`

		// Execute a query
		resultSet, err := session.Execute(sql)
		if err != nil {
			fmt.Print(err.Error())
			return
		}
		fmt.Println(resultSet)
		for _, v := range resultSet.GetRows() {
			fmt.Println(string(v.GetValues()[0].SVal))
			fmt.Println(string(v.GetValues()[1].SVal))
			fmt.Println(string(v.GetValues()[2].SVal))
			fmt.Println(string(v.GetValues()[3].SVal))
			fmt.Println(string(v.GetValues()[4].SVal))
		}
	}

	fmt.Print("\n")
	log.Info("Nebula Go Client Basic Example Finished")
}

output:

&{0xc0000e60e0 [id name batchno process pass] map[batchno:2 id:0 name:1 pass:4 process:3] {0 [85 84 67]}}

问题已经解决。之前我写的sql是这样：

use manager;MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc;

注意上面是两个sql语句连在一起的，先是 use manager 指定空间，再是具体的业务sql。这样的写法在服务器版本3.2.0是可以正常工作的。

现在我升级到了服务器3.4.0，上面的写法就不行了。两句sql必须分开执行。不知这样的表现行为是有意这么设计，还是前后不兼容的bug？

[wey-gu]

ping @Aiee

[pythonsan]

我使用的也是3.2.0版本，但是呢如果use和查询语句放在一起也是无法查询出来数据的 :-(
分开Execute()就可以查询出来，是因为use space有延时吗？

[QingZ11]

go code:

/*
 
 * Copyright (c) 2021 vesoft inc. All rights reserved.
 *
 * This source code is licensed under Apache 2.0 License.
 *
 */

package main

import (
	"fmt"

	nebula "github.com/vesoft-inc/nebula-go/v3"
)

const (
	address = "124.222.227.15"
	// The default port of NebulaGraph 2.x is 9669.
	// 3699 is only for testing.
	port     = 9669
	username = "root"
	password = "nebula"
)

// Initialize logger
var log = nebula.DefaultLogger{}

func main() {
	hostAddress := nebula.HostAddress{Host: address, Port: port}
	hostList := []nebula.HostAddress{hostAddress}
	// Create configs for connection pool using default values
	testPoolConfig := nebula.GetDefaultConf()

	// Initialize connection pool
	pool, err := nebula.NewConnectionPool(hostList, testPoolConfig, log)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to initialize the connection pool, host: %s, port: %d, %s", address, port, err.Error()))
	}
	// Close all connections in the pool
	defer pool.Close()

	// Create session
	session, err := pool.GetSession(username, password)
	if err != nil {
		log.Fatal(fmt.Sprintf("Fail to create a new session from connection pool, username: %s, password: %s, %s",
			username, password, err.Error()))
	}
	// Release session and return connection back to connection pool
	defer session.Release()

	{
		// Prepare the query
		sql := `use manager;MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc 
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc
				UNION
				MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})-[e:follow*0]->(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass;`

		// Execute a query
		resultSet, err := session.Execute(sql)
		if err != nil {
			fmt.Print(err.Error())
			return
		}
		fmt.Println(resultSet)
		for _, v := range resultSet.GetRows() {
			fmt.Println(string(v.GetValues()[0].SVal))
			fmt.Println(string(v.GetValues()[1].SVal))
			fmt.Println(string(v.GetValues()[2].SVal))
			fmt.Println(string(v.GetValues()[3].SVal))
			fmt.Println(string(v.GetValues()[4].SVal))
		}
	}

	fmt.Print("\n")
	log.Info("Nebula Go Client Basic Example Finished")
}

output:

&{0xc0000e60e0 [id name batchno process pass] map[batchno:2 id:0 name:1 pass:4 process:3] {0 [85 84 67]}}

问题已经解决。之前我写的sql是这样：

use manager;MATCH (v:node{batchno: "BF14CDZ1-210107A1-02"})<-[e:follow*]-(v2) RETURN 
				distinct v2.node.id as id, v2.node.name as name, 
				v2.node.batchno as batchno, v2.node.process as process, 
				v2.node.pass as pass ORDER BY id asc;

注意上面是两个sql语句连在一起的，先是 use manager 指定空间，再是具体的业务sql。这样的写法在服务器版本3.2.0是可以正常工作的。

现在我升级到了服务器3.4.0，上面的写法就不行了。两句sql必须分开执行。不知这样的表现行为是有意这么设计，还是前后不兼容的bug？

hi， @supermario1990 我记得之前有一个 bug 是用户 use space 和 rebuild index 的操作一起，触发了某个 bug，还有 use space 之后不能识别后面的语句（参考这个帖子：https://discuss.nebula-graph.com.cn/t/topic/12707/10?u=steam ）所以应该是在某个版本开始，use space 要和具体的 query 语句分开了（抱歉我已经不大记得具体的版本号了） cc @wey-gu @pythonsan

Hi, @ supermario1990 I remember previously there was a bug where users use use space and rebuild index operations together, triggering a certain bug. Also after use space, the subsequent statements could not be recognized (refer to this post: https://discuss.nebula-graph.com.cn/t/topic/12707/10?u=steam) So it should be that starting from a certain version, use space needs to be separated from the specific query statements (sorry I don't really remember the exact version number anymore).