SPM: unexpected behavior in parallel creation of global binding

[ChenPeng2013]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

cluster config
2 tidb
1 pd
1 tikv

use test;
create table t(a int, b int, index idx(a));

run a minute and ctrl +c

package main

import (
	"context"
	"database/sql"
	"fmt"
	_ "github.com/go-sql-driver/mysql"
	"time"
)

func main() {
	go run("root:@tcp(192.168.228.83:4000)/test?charset=utf8&parseTime=True")
	run("root:@tcp(192.168.228.83:4001)/test?charset=utf8&parseTime=True")
}

func run(dsn string) {
	db, err := sql.Open("mysql", dsn)
	if err != nil {
		panic(err)
	}
	defer db.Close()
	
	for i := 0; i < 1; i++ {
		go func() {
			c, err := db.Conn(context.Background())
			if err != nil {
				panic(err)
			}
			defer c.Close()
			
			for {
				ss := []string{
					"create global binding for select * from t using select * from t",
				}
				for _, s := range ss {
					fmt.Println(s, time.Now())
					if _, err := c.ExecContext(context.Background(), s); err != nil {
						panic(err)
					}
				}
			}
		}()
	}
	time.Sleep(1 * time.Hour)
}

show global bindings;
select * from mysql.bind_info where status != "deleted";
admin reload bindings;
show global bindings;

2. What did you expect to see? (Required)

mysql> show global bindings;
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| Original_sql    | Bind_sql        | Default_db | Status | Create_time             | Update_time             | Charset | Collation | Source |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| select * from t | select * from t | test       | using  | 2020-11-25 03:55:50.609 | 2020-11-25 03:55:50.609 | utf8    | utf8_bin  | manual |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
1 row in set (0.00 sec)

mysql> select * from mysql.bind_info where status != "deleted";
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| original_sql    | bind_sql        | default_db | status | create_time             | update_time             | charset | collation | source |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| select * from t | select * from t | test       | using  | 2020-11-25 03:55:50.508 | 2020-11-25 03:55:50.508 | utf8    | utf8_bin  | manual |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
1 row in set (0.01 sec)

mysql> admin reload bindings;
Query OK, 0 rows affected (0.01 sec)

mysql> show global bindings;
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| Original_sql    | Bind_sql        | Default_db | Status | Create_time             | Update_time             | Charset | Collation | Source |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| select * from t | select * from t | test       | using  | 2020-11-25 03:55:50.609 | 2020-11-25 03:55:50.609 | utf8    | utf8_bin  | manual |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
1 row in set (0.00 sec)

3. What did you see instead (Required)

mysql> show global bindings;
Empty set (0.00 sec)

mysql> select * from mysql.bind_info where status != "deleted";
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| original_sql    | bind_sql        | default_db | status | create_time             | update_time             | charset | collation | source |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
| select * from t | select * from t | test       | using  | 2020-11-25 03:55:50.508 | 2020-11-25 03:55:50.508 | utf8    | utf8_bin  | manual |
+-----------------+-----------------+------------+--------+-------------------------+-------------------------+---------+-----------+--------+
1 row in set (0.01 sec)

mysql> admin reload bindings;
Query OK, 0 rows affected (0.01 sec)

mysql> show global bindings;
Empty set (0.01 sec)

4. What is your TiDB version? (Required)

Release Version: v4.0.0-beta.2-1630-g7a19c709d
Edition: Community
Git Commit Hash: 7a19c709d07d4c33009bb85bba5122b2a658505b
Git Branch: master
UTC Build Time: 2020-11-24 11:57:15
GoVersion: go1.13
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false

[ti-srebot]

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