MySQL 8.0 Reference Manual Including MySQL NDB Cluster 8.0
The Performance Schema table described here is available as
of MySQL 8.0.14. Prior to MySQL 8.0.14, use the
corresponding INFORMATION_SCHEMA table
instead; see
Section 28.5.4, “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_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 29.6 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.
This column was added in MySQL 8.0.32.
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.
This column was added in MySQL 8.0.32.
The tp_thread_state table has
these indexes:
Unique index on (TP_GROUP_ID,
TP_THREAD_NUMBER)
TRUNCATE TABLE is not permitted
for the tp_thread_state table.