Server System Variables Command-Line Format --thread-pool-max-unused-threads=# System Variable thread_pool_max_unused_threads Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 0 Minimum Value 0 Maximum Value 4096 The maximum permitted number of unused threads in the thread pool. This variable makes it possible to limit the amount of memory used by sleeping threads. A value of 0 (the default) means no limit on the number of sleeping threads. A value of  N  where  N  is greater than 0 means 1 consumer thread and  N − 1 reserve threads. In this case, if a thread is ready to sleep but the number of sleeping threads is already at the maximum, the thread exits rather than going to sleep. A sleeping thread is either sleeping as a consumer thread or a reserve thread. The thread pool permits one thread to be the consumer thread when sleeping. If a thread goes to sleep and there is no existing consumer thread, it sleeps as a consumer thread. When a thread must be woken up, a consumer thread is selected if there is one. A reserve thread is selected only when there is no consumer thread to wake up. This variable is available only if the thread pool plugin is enabled. See Section 5.6.3, “MySQL Enterprise Thread Pool” . • thread_pool_prio_kickup_timer This variable affects statements waiting for execution in the low-priority queue. The value is the number of milliseconds before a waiting statement is moved to the high-priority queue. The default is 1000 (1 second). This variable is available only if the thread pool plugin is enabled. See Section 5.6.3, “MySQL Enterprise Thread Pool” . 904 Command-Line Format --thread-pool-prio-kickup-timer=# System Variable thread_pool_prio_kickup_timer Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 1000 Minimum Value 0 Maximum Value 4294967294