MySQL :: MySQL 8.4 Reference Manual :: 29.12.16.4 The tp_thread_state Table (original) (raw)

29.12.16.4 The tp_thread_state Table

The tp_thread_state table has one row per thread created by the thread pool to handle connections.

The tp_thread_state table has these columns:

• TP_GROUP_ID
  The thread group ID.
• TP_THREAD_NUMBER
  The ID of the thread within its thread group.TP_GROUP_ID andTP_THREAD_NUMBER together provide a unique key within the table.
• PROCESS_COUNT
  The 10ms interval in which the statement that uses this thread is currently executing. 0 means no statement is executing, 1 means it is in the first 10ms, and so forth.
• WAIT_TYPE
  The type of wait for the thread. NULL means the thread is not blocked. Otherwise, the thread is blocked by a call to thd_wait_begin() and the value specifies the type of wait. The_`xxx`__WAIT columns of thetp_thread_group_stats table accumulate counts for each wait type.
  The WAIT_TYPE value is a string that describes the type of wait, as shown in the following table.
  Table 29.4 tp_thread_state Table WAIT_TYPE Values

  Wait Type	Meaning
  THD_WAIT_SLEEP	Waiting for sleep
  THD_WAIT_DISKIO	Waiting for Disk IO
  THD_WAIT_ROW_LOCK	Waiting for row lock
  THD_WAIT_GLOBAL_LOCK	Waiting for global lock
  THD_WAIT_META_DATA_LOCK	Waiting for metadata lock
  THD_WAIT_TABLE_LOCK	Waiting for table lock
  THD_WAIT_USER_LOCK	Waiting for user lock
  THD_WAIT_BINLOG	Waiting for binlog
  THD_WAIT_GROUP_COMMIT	Waiting for group commit
  THD_WAIT_SYNC	Waiting for fsync

• TP_THREAD_TYPE
  The type of thread. The value shown in this column is one of CONNECTION_HANDLER_WORKER_THREAD,LISTENER_WORKER_THREAD,QUERY_WORKER_THREAD, orTIMER_WORKER_THREAD.
• THREAD_ID
  This thread's unique identifier. The value is the same as that used in the THREAD_ID column of the Performance Schemathreads table.
• TIME_OF_ATTACH:
  Timestamp showing when the thread was attached, if attached to a connection; otherwiseNULL.
• MARKED_STALLED:
  This is True if this thread has been marked as stalled by the stall checker thread.
• STATE:
  Possible values depend on the type of thread, as shown by the TP_THREAD_TYPE column:
  • For worker threads (QUERY_WORKER_THREAD), this is one of Managing,Polling, Processing Direct, Processing Queued, Sleeping Consumer, or Sleeping Reserve.
  • For connection handler threads (CONNECTION_HANDLER_WORKER_THREAD), this is one of CH Processing,CH Sleeping Timed, or CH Sleeping Indefinite.
  • For the stall checker thread (TIMER_WORKER_THREAD), this is one of SC Checking, SC Sleeping Short, or SC Sleeping Long.
• EVENT_COUNT:
  The accumulated number of events processed by this thread.
• ACCUMULATED_EVENT_TIME:
  The wall clock time spent processing events.
• EXEC_COUNT:
  The accumulated number of queries (statements) passed to the server for execution.
• ACCUMULATED_EXEC_TIME:
  The wall clock time spent processing queries by the server.

The tp_thread_state table has one index; this is a unique index on theTP_GROUP_ID andTP_THREAD_NUMBER columns.

TRUNCATE TABLE is not permitted for the tp_thread_state table.