The cluster module allows us to create worker processes to improve our NodeJS applications performance. This is specially important in web applications, where a master process receives all the requests and load balances them among the worker processes.
But all this power comes with the cost that must be the application who manages all the complexity associated with process managements: what happens if a worker process exists unexpectedly, how exit gracefully the worker processes, what if you need to restart all your workers, etc.
In this post we present PM2 tool. although it is a general process manager, that means it can manage any kind of process like python, ruby, … and not only NodeJS processes, the tool is specially designed to manage NodeJS applications that want to work with the cluster module.»