Heap stable while rss increases node.js

Question

I have an app written in node.js and it works as it should. The only problem is that the memory keeps increasing 'till it hits 1.3Gb and immediately drops to ~400Mb. At first I though it's a memory leak, but further investigation shows there's no leaks.

The analyze of heap-dump doesn't give any useful information, just proves that there's no leak. I'm using node.js v4.2.1 and the application is heavily using websockets (socket.io) with transports set to ['websockets'] only. For load balancing I'm using PM2 in cluster mode (4 instances) .

What could be the reason? What are the consequences? Do you think it might crash the server in the long run?

Answer 1

If you plan to distribute the load of connections among different processes or machines with pm2 , you have to make sure that requests associated with a particular session id connect to the process that originated them. If it connect wrong process , it will make a mass of request ajax to server . You can use inspector in browser to check it, refresh web an check socket run correctly. It will make memory increase faster and when it to limit , It will call gc().