Have you ever encountered a deadlock problem in MySQL? How did you solve it?

The necessary conditions for deadlock are 4 individual ：
mutual exclusion ： Over a period of time , A certain resource of the computer can only be occupied by one process . here , If another process requests the resource , We have to wait
The condition of indivisibility ： The resources obtained by a process are used up before , It can't be taken away by other processes , It can only be released actively by the process that obtains the resource
Request and hold conditions ： The process has obtained at least one resource , And ask for other resources , But the requested resource is already occupied by another process , At this point, the requested process will be blocked , And will not release their own resources
Loop wait condition ： Processes in the system wait for each other , At the same time, the resources occupied by each process will be requested by the next process . For example, there are processes A、 process B And processes C Three processes , process A The requested resource is by the process B Occupy , process B The requested resource is by the process C Occupy , process C The requested resource is by the process A Occupy , So a circular waiting condition is formed , As shown in the figure below ：

Deadlock prevention ： The most direct way to deal with deadlock is to destroy the 4 One or more of the necessary conditions , To prevent deadlock .
Avoid deadlock ： During the allocation of system resources , Use a strategy or method to prevent the system from entering an unsafe state , So as to avoid deadlock .
Detection of deadlock ： This method allows the system to deadlock during operation , But it can detect the occurrence of deadlock , And take appropriate measures to clear the deadlock .
Deadlock Relieving ： When deadlock is detected , Adopt appropriate strategies and methods to free the process from deadlock .