6.4 The INFORMATION_SCHEMA 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 and TP_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 the TP_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 6.2 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