Philly ETE 2015 #7 – Monica Beckwith – GC Tuning Confessions of a Performance Engineer

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Slides from Monica’s talk are also available here.


Performance tuning is a methodical and an iterative process. It is imperative to have a performance plan coexist with a product development plan. A performance plan not only serves to document the requirements but also feeds into designing the performance experiments and helps in providing a clear understanding of the performance infrastructural needs.

As a JVM/GC performance engineer – I always ask pertinent questions such as – what are performance expectations of the product by the stakeholders? what are the important metrics?, what are the tuning goals?, etc. and then I discuss tradeoffs and finally establish tuning goals.

During this session, I will discuss these questions, tradeoffs and goals and I will also talk about my experience with three garbage collectors in OpenJDK’s HotSpot JVM – Parallel Old, CMS and G1 and compare and contrast them.

About Monica:

Monica Beckwith is a Java Performance Consultant. She was the Java Garbage First Garbage Collector Performance Lead at Oracle. Her past experiences include working with Oracle/Sun and AMD optimizing the JVM for server class systems. Monica was voted a Rock Star speaker @JavaOne 2013. You can follow Monica on twitter @mon_beck.