What is basic approach to look into out of memory issue ?

• Identify nature of memory issue

1. Is it due to spike in usage?

There is a possibility that application is running fine till 100 user but when user count increased to 200 there is spike in memory usage and system throw out of memory error

     2. Is it memory leak?

There is a possibility that developers written a bad code lead to unwanted uses of memory by application and probem in freeing up memory , in this kind of issue we will see that there are GC happening in the application but application memory usage is almost constant. What i mean to say is even GC is happening but memory freeing is very small or nothing.

• Once you have successfully identify the problem you can open the memory dump using MAT and analyse the usage further  for RCA