When disabling garbage collectors in Java

Question

I recently heard Kirk Pepperdin talk about changing garbage collectors for better performance - but what exactly does this mean and what makes the garbage collector better or different than the other?

Answer 1

You ask two questions:

What does changing garbage collectors in Java mean for better performance?

This is a huge topic and, like some other respondents, I highly recommend you read it. I recommend Java SE 6 HotSpot [tm] Configuring a virtual machine for garbage collection from Sun. The information below mainly comes from there. The article "turbo-charge" java recommended in another answer is older.

In short, one of the many options we have when starting the JVM is to select a garbage collector, of which there are currently three:

• Serial collector (selected with the -XX: + UseSerialGC option) - a single thread is used to work with the collection, and everyone waits for this to happen.
• Parallel collector (selected with the -XX: + UseParallelGC option) - this makes small collections (of the younger generation) in parallel, but waits for everything during the main collections.
• ( -XX: + UseConcMarkSweepGC) - .

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