https://www.percona.com/doc/percona-server/5.6/performance/threadpool.html
https://mariadb.com/kb/en/mariadb/thread-pool-in-mariadb/#optimizing-server-variables-on-unix
https://www.percona.com/blog/2014/01/23/percona-server-improve-scalability-percona-thread-pool/
某台负载一直很高的数据库服务器,启用之后,load 下降了很多。

启用方法,在 my.cnf 中加入:
thread_handling = pool-of-threads