The first in a series of interactive sessions discussing the state of garbage collection in 2018 takes place on May 1st. Experts including Martijn Verburg, Richard Warburton and John Oliver will be taking part, sharing their knowledge on all things garbage collection related. We spoke to Martijn and Richard to get their take on the event.

1. Who do you think should come along?

MW: Any Java developers (or developers who write code on the JVM) who care about how their code performs on the JVM, especially in small (e.g. uService apps) or large (e.g. Big Data style apps)
RW: Java developers who have a solid grasp of the basic language and tool chain and want to understand more about how the JVM works under the hood and how to make better use of the garbage collection subsystem.

2. What is your background in GC?

MW: I’m the CEO of jClarity, a tooling company that specialises in GC analysis. I have a decent understanding of GC algorithms and performance tuning, but certainly not at the level of the world’s experts (some of who are in jClarity’s engineering team)!
RW: I’ve worked previously (and currently) for JVM tool vendors who wrote tooling around GC logs and understanding GC. I’ve also done bespoke development and consulting work on problems that have low latency requirements and thus have an interaction with GC tooling.

3. Why do you think it’s such an important topic to get right?

MW: When Java Garbage collects it often has a Stop the World (STW) phase, which brings the whole JVM to a stop, this can greatly impact end user / system experience depending on how often those pauses occur and how long each pause occurs for.
RW: Performance is a big driver of business value. To put it simply happy customers are a great thing to have and customers aren’t happy when their website is unresponsive. It can also be a strong driver of business value in spaces such as AdTech or HFT where low latency really matters.

4. What do you think are the three most interesting questions that this event will answer?

1) What has changed in Java 9+ with regards to GC behaviour?
2) What’s the future direction of GC in Java?
3) How do I tune GC for my small container based uService apps?
1) How do I know when I have a GC problem?
2) What is changing around GC in future Java versions?
3) How do I understand when to look at GC rather than other application problems.

5. Any advice for junior programmers entering the industry?

MW: Whatever they tell you, it’s a people problem! So even with a technical event like a GC Panel, there’s always a strong human element. How does GC impact people, what performance characteristics do people care about? How do we help people tune etc?
RW: Have fun.

The Garbage Collection 2018 event promises to be an interesting and informative evening, so come along and see what you can learn. It’s a great opportunity to join in with an analysis of changes in Java 9, tuning your application, extracting information out of the JVM, tooling to aid interpretation, and looking at and beyond OpenJDK/Oracle JDK.
You’ll also be able to find out about the best sources of garbage collection information and where to find them.

If you are involved with garbage collection in any capacity within your organization, or you just have an interest in the topic, this is a chance to increase your understanding and advance your knowledge.

If you’re interested, then sign up to reserve your place:, and join the Slack Group at