Golang : Ways to recover memory during run time.

Problem :

Most program written with Golang should have automatic garbage collection to recover the used memory. However, there are times when your program process large amount of data in memory or run for a long time and you want to trigger garbage collection manually. How to do that ?

Solution :

Use runtime/debug.FreeOSMemory() function or runtime.GC() function.

Chances are ... your code will be compiled into a binary and deployed at a server. It will be great if your program can accept parameter such as at what time to trigger a manual garbage collection. Time such as ... when everyone is asleep or off peak hours.

NOTE : Many years ago when I was a sys admin in Vodafone New Zealand. The Java program that I was looking after will trigger a garbage collection during peak office hours... effectively locking out every users for 45 to 70 minutes! The only way to shorten the process ... is to reboot the server! As a developer, it is your responsibility to ensure manual garbage collection does not run for long time(less than 1 minute) and create bad user experience.

References :

http://golang.org/pkg/runtime/#GC

http://golang.org/pkg/runtime/debug/#FreeOSMemory