MySQL 8.4 Reference Manual Including MySQL NDB Cluster 8.4
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_WAITtp_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, or
TIMER_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 Schema
threads table.
TIME_OF_ATTACH:
Timestamp showing when the thread was attached, if
attached to a connection; otherwise
NULL.
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 the
TP_GROUP_ID and
TP_THREAD_NUMBER columns.
TRUNCATE TABLE is not permitted
for the tp_thread_state table.