21.30 Thread Pool INFORMATION_SCHEMA Tables

21.30.1 The INFORMATION_SCHEMA TP_THREAD_STATE Table
21.30.2 The INFORMATION_SCHEMA TP_THREAD_GROUP_STATE Table
21.30.3 The INFORMATION_SCHEMA TP_THREAD_GROUP_STATS Table

The following sections describe the INFORMATION_SCHEMA tables associated with the thread pool plugin. They provide information about thread pool operation:

Rows in these tables represent snapshots in time. In the case of TP_THREAD_STATE, all rows for a thread group comprise a snapshot in time. Thus, the MySQL server holds the mutex of the thread group while producing the snapshot. But it does not hold mutexes on all thread groups at the same time, to prevent a statement against TP_THREAD_STATE from blocking the entire MySQL server.

The thread pool INFORMATION_SCHEMA tables are implemented by individual plugins and the decision whether to load one can be made independently of the others (see Section 8.11.6.1, “Thread Pool Components and Installation”). However, the content of all the tables depends on the thread pool plugin being enabled. If a table plugin is enabled but the thread pool plugin is not, the table becomes visible and can be accessed but will be empty.