Bug #119223 The pfs_thread.processlist_id is set to NULL after using Srv_session

• Submitted: 24 Oct 3:16
• Reporter: yl deng
• Status: Open
• Category: MySQL Server
• Severity: S3 (Non-critical)
• Version: 8.0.30
• OS: Any
• CPU Architecture: Any
• Tags: The pfs_thread.processlist_id is set to NULL after using Srv_session

[24 Oct 3:16] yl deng

Description:
The pfs_thread changes when a thread uses Srv_session. Since Srv_session is used in group_replication_reset_member_actions(), calling this function will set the pfs_thread.processlist_id to NULL. The relevant code in Srv_session::detach() shows that the pfs_thread is reset:

``` 
bool Srv_session::detach() {
......
#ifdef HAVE_PSI_THREAD_INTERFACE
  set_psi(nullptr);
#endif
......
}

static void set_psi(THD *thd) {
  struct PSI_thread *psi = PSI_THREAD_CALL(get_thread)();
  PSI_THREAD_CALL(set_thread_id)(psi, thd ? thd->thread_id() : 0);
  PSI_THREAD_CALL(set_thread_THD)(psi, thd);
}

```

How to repeat:
mysql> select * from performance_schema.threads where processlist_id = connection_id()\G
*************************** 1. row ***************************
          THREAD_ID: 53
               NAME: thread/sql/one_connection
               TYPE: FOREGROUND
     PROCESSLIST_ID: 16
   PROCESSLIST_USER: root
   PROCESSLIST_HOST: localhost
     PROCESSLIST_DB: NULL
PROCESSLIST_COMMAND: Query
   PROCESSLIST_TIME: 0
  PROCESSLIST_STATE: executing
   PROCESSLIST_INFO: select * from performance_schema.threads where processlist_id = connection_id()
   PARENT_THREAD_ID: NULL
               ROLE: NULL
       INSTRUMENTED: YES
            HISTORY: YES
    CONNECTION_TYPE: SSL/TLS
       THREAD_OS_ID: 69122
     RESOURCE_GROUP: USR_default
   EXECUTION_ENGINE: PRIMARY
1 row in set (0.01 sec)

mysql> install plugin group_replication soname 'group_replication.so';
Query OK, 0 rows affected (0.05 sec)

mysql> select group_replication_reset_member_actions();
+------------------------------------------+
| group_replication_reset_member_actions() |
+------------------------------------------+
| OK                                       |
+------------------------------------------+
1 row in set (0.02 sec)

mysql> select * from performance_schema.threads where processlist_id = connection_id()\G
Empty set (0.00 sec)

mysql> select * from performance_schema.threads where thread_id = 53\G
*************************** 1. row ***************************
          THREAD_ID: 53
               NAME: thread/sql/one_connection
               TYPE: BACKGROUND
     PROCESSLIST_ID: NULL
   PROCESSLIST_USER: root
   PROCESSLIST_HOST: localhost
     PROCESSLIST_DB: NULL
PROCESSLIST_COMMAND: NULL
   PROCESSLIST_TIME: 0
  PROCESSLIST_STATE: statistics
   PROCESSLIST_INFO: select * from performance_schema.threads where thread_id = 53
   PARENT_THREAD_ID: NULL
               ROLE: NULL
       INSTRUMENTED: YES
            HISTORY: YES
    CONNECTION_TYPE: SSL/TLS
       THREAD_OS_ID: 69122
     RESOURCE_GROUP: USR_default
   EXECUTION_ENGINE: PRIMARY
1 row in set (0.00 sec)