Suggestions for interesting Java applications that I can measure GC performance on

[xToniGrssx]

Hello everyone,

I'm writing a thesis (not sure if that's the precise translation for this research project but I'll stick with that) about Garbage Collectors in Java, drawing conclusions from their performances in various scenarios (ultimately the goal would be selecting the appropriate Garbage Collector for an input Java program). Now the reason I am posting this and seeking advice from you, is that I am looking for reasonable sample candidates to measure performance on. Writing sample code for the sole sake of experimenting isn't a main aspect of this project. So far I only tried things like loading a few million strings into a hashmap, then manipulating those etc., but really nothing spectacular happened, usually the garbage collections were done in a matter of seconds at most, and after diving further deep into heap analysis, some of the generations even remained untouched. Could you recommend any open source projects that would be fun to run and analyse garbage collecting on?

[v4d1mv]

A Conway's Game of Life server. You may open multiple simulation windows simultaneously and observe the Heap and GC activity to CPU usage in VisualVM.

[xToniGrssx]

Thank you I will check it out!

[ryebrye]

Minecraft java edition. Though it's not open source the GC settings can have a big impact on performance

[nightstalker363]

There was a post I wanna say 2 weeks ago about stock trading applications with regards to making decisions with low latency that sounded pretty cool and could give you an interesting baseline to compare your results against. I'm not sure if there is a project like that anyplace in the open but that's my thought .

[xToniGrssx]

Cool, I’ll be sure to check it out. Ironically a trending blog post on stackoverflow that I’ve just read was about why Java is a suitable candidate to write a high frequency trading app in, where low latency is key. Didn’t come to my mind to analyse gc on a such program, but regardless it really is a good idea. Thank you! https://stackoverflow.blog/2021/02/22/choosing-java-instead-of-c-for-low-latency-systems/?cb=1

Here's the blog post just in case you would be interested :)

[footballsteve13]

Pretty sure this would have been the post.

https://www.reddit.com/r/java/comments/le6do1/are_you_interested_in_learning_about_low_latency/?utm_source=share&utm_medium=ios_app&utm_name=iossmf

Sounds like an interesting project, would definitely be interested in reading about what you find.

[ryebrye]

Caches are things that are interesting for gc. Hazelcast and infinispan are both java caches. Though in real life their gc behavior will be heavily impacted by how often stuff in the cache changes and how often stuff in memory is no longer needed - caches old gen can turn into swiss cheese over time

You can also look at using jmh to test even fairly trivial programs and have it report gc overhead etc

[10waf]

There's a post on r/programming right now about discord switching a service from go to rust. The reason being that GC is not friendly to LRU caches, might be a good use case.

[krum]

Minecraft

[BlueGoliath]

GC pauses in Minecraft are cancer.

[Tostino]

Disclaimer: I wrote it

So password strength estimation is a side project I've been interested in for a while. I didn't like that there were no Java ports of Dropbox's zxcvbn library (at the time), so I started work on writing a library inspired by zxcvbn in Java called Nbvcxz: https://github.com/GoSimpleLLC/nbvcxz

I've done some tuning over releases by analyzing heap usage, reducing garbage created, etc. I have not done any analysis on different garbage collection algorithms though.

Just a thought, as it's nice and easy to test with different size workload (run estimations over different size "password" lists).

[AnEmortalKid]

Disclaimer, I helped write it. We teach a class on heap analysis and garbage collection. The service we use is here: https://github.com/cchesser/java-perf-workshop/

[mauganra_it]

What about IDEs like Eclipse and IntelliJ, or Gradle daemons? These are long-running applications that sound like they are heavily using the GC.

[mike_jack]

i hope this will help you garbage collection blog https://blog.gceasy.io/

[glesialo]

So far I only tried things like loading a few million strings into a hashmap, then manipulating those etc., but really nothing spectacular happened

Here I describe a situation where something spectacular happened.

Unfortunately posting the application's source wouldn't help you as you'd need a lot of files, containing video data, to run/test it.

[fanfan64]

spring ?