mysql里show full processlist，进程很少

Question

APP和网站每时每刻都有人在访问，只是量不多，但在mysql里show full processlist，却只有几个进程，这是什么原因？

Answer 1

MySQL storage engine belongs to or supports MVCC, supports concurrency and I/O multiplexing. It is thought that the client communicates with the mysql client in the form of a TCP connection. Under normal circumstances, the client will use the already established connection and will not create a new connection every time SQL is executed (from the perspective of resources and efficiency). If the instantaneous traffic is large, the client should create multiple connections to implement asynchronous non-blocking processing in this form. Each TCP connection will have a disconnect waiting time. If it has not been used by this time, it will be destroyed. , show full processlist actually sees these connections. These are the functions of the client mysql plug-in connection pool.