MySQL 9.5 Reference Manual Including MySQL NDB Cluster 9.5
          The tp_thread_group_state table
          has one row per thread group in the thread pool. Each row
          provides information about the current state of a group.
        
          The tp_thread_group_state table
          has these columns:
        
              TP_GROUP_ID
            
The thread group ID. This is a unique key within the table.
              CONSUMER THREADS
            
The number of consumer threads. There is at most one thread ready to start executing if the active threads become stalled or blocked.
              RESERVE_THREADS
            
The number of threads in the reserved state. This means that they are not started until there is a need to wake a new thread and there is no consumer thread. This is where most threads end up when the thread group has created more threads than needed for normal operation. Often a thread group needs additional threads for a short while and then does not need them again for a while. In this case, they go into the reserved state and remain until needed again. They take up some extra memory resources, but no extra computing resources.
              CONNECT_THREAD_COUNT
            
The number of threads that are processing or waiting to process connection initialization and authentication. There can be a maximum of four connection threads per thread group; these threads expire after a period of inactivity.
              CONNECTION_COUNT
            
The number of connections using this thread group.
              QUEUED_QUERIES
            
The number of statements waiting in the high-priority queue.
              QUEUED_TRANSACTIONS
            
The number of statements waiting in the low-priority queue. These are the initial statements for transactions that have not started, so they also represent queued transactions.
              STALL_LIMIT
            
              The value of the
              thread_pool_stall_limit
              system variable for the thread group. This is the same
              value for all thread groups.
            
              PRIO_KICKUP_TIMER
            
              The value of the
              thread_pool_prio_kickup_timer
              system variable for the thread group. This is the same
              value for all thread groups.
            
              ALGORITHM
            
              The value of the
              thread_pool_algorithm
              system variable for the thread group. This is the same
              value for all thread groups.
            
              THREAD_COUNT
            
The number of threads started in the thread pool as part of this thread group.
              ACTIVE_THREAD_COUNT
            
The number of threads active in executing statements.
              STALLED_THREAD_COUNT
            
The number of stalled statements in the thread group. A stalled statement could be executing, but from a thread pool perspective it is stalled and making no progress. A long-running statement quickly ends up in this category.
              WAITING_THREAD_NUMBER
            
If there is a thread handling the polling of statements in the thread group, this specifies the thread number within this thread group. It is possible that this thread could be executing a statement.
              OLDEST_QUEUED
            
How long in milliseconds the oldest queued statement has been waiting for execution.
              MAX_THREAD_IDS_IN_GROUP
            
              The maximum thread ID of the threads in the group. This is
              the same as
              MAX(TP_THREAD_NUMBER) for
              the threads when selected from the
              tp_thread_state table. That
              is, these two queries are equivalent:
            
SELECT TP_GROUP_ID, MAX_THREAD_IDS_IN_GROUP FROM tp_thread_group_state; SELECT TP_GROUP_ID, MAX(TP_THREAD_NUMBER) FROM tp_thread_state GROUP BY TP_GROUP_ID;
              EFFECTIVE_MAX_TRANSACTIONS_LIMIT
            
              The effective
              max_transactions_limit_per_tg value for
              the group.
            
              NUM_QUERY_THREADS
            
The number of worker threads in the group.
              TIME_OF_LAST_THREAD_CREATION
            
The point in time when the thread was last created.
              NUM_CONNECT_HANDLER_THREAD_IN_SLEEP
            
The number of inactive connection handler threads.
              THREADS_BOUND_TO_TRANSACTION
            
              The number of threads in an active transaction, which must
              be less than
              thread_pool_max_transactions_limit;
              this is set only when
              thread_pool_max_transactions_limit is
              not 0.
            
              QUERY_THREADS_COUNT
            
same as num_query_threads, but used for different purposes?
              TIME_OF_EARLIEST_CON_EXPIRE
            
A timestamp showing the earliest point in time when a connection is expected to expire.
          The tp_thread_group_state table
          has one index; this is a unique index on the
          TP_GROUP_ID column.
        
          TRUNCATE TABLE is not permitted
          for the tp_thread_group_state
          table.