thread_concurrency

thread_concurrency should follow: number of CPU’s*2 for thread_concurrency thread_concurrency -> the number of processes which will run AT SAME TIME. In all modern OSs possible to run a lot of tasks simultaneously. But in real one processor will perform ONE task at once but very frequently switch between tasks. If you have few CPUs it possible to run few tasks really simultaneously. Recomended value « Number of CPU’s x 2 » is for dedicated mysql servers only. If you run a lot of other daemons (like apache, mail servers, etc.) it may be useful to set thread_concurrency to value equal to « Number of CPU » or even lower. It may depends on type of you SQL queries and system configuration.