Erik Österlund
@eosterlund.bsky.social
OpenJDK HotSpot JVM developer at Oracle. Drinks coffee and pets cats. Opinions expressed are, unsurprisingly, my own.
Today, May 22, my book about ZGC is finally ready and available to order! I can recommend reading it if you want to learn more about the magic nature of ZGC. You can order it here (among many places): www.routledge.com/The-Z-Garbag...
The Z Garbage Collector: In JDK 25
This book explains how the Z Garbage Collector was designed, why it was designed this way, the common pitfalls to avoid when using ZGC in JDK 25 and how to get useful information from the garbage coll...
routledge.com
Wow you got that fast! Hope you enjoy it! Best experienced with a big cup of coffee.
Stefan Marr@stefan-marr.de · 3mo agoLooking forward to reading it!
#Java peers, #JavaOne 2026 is right around the corner! Read my LinkedIn article to learn more about the conference's value...and of course, register now! www.linkedin.com/pulse/javaon...
JavaOne...30 Years of Java and the Community That Keeps It Moving
Register Now for JavaOne 2026 | March 17-19 | Redwood City, California For three decades, Java has been a constant in an industry defined by change. Frameworks come and go, architectures shift, and ha...
linkedin.com
After working on ZGC for a decade, I’m happy to announce that I’m publishing a book about ZGC in JDK 25. It ships 22 May (www.taylorfrancis.com/books/mono/1...) and is being published by Taylor & Francis. You should get a copy if you want to learn more about ZGC. It’s available for pre-order now.
The Z Garbage Collector | In JDK 25 | Erik Österlund | Taylor & Franci
This book explains how the Z Garbage Collector was designed, why it was designed this way, the common pitfalls to avoid when using ZGC in JDK 25 and how to get
taylorfrancis.com
📢Important Update 📢 Many have asked for more time to submit to the 2026 #JavaOne call for papers. We've extended the deadline until Nov 13th at 11:59pm PT. Be sure to submit your #Java proposal(s) before time runs out: ➡️ social.ora.cl/6013A7UXF
JDK 25 has been branched from the main line and is now in Rampdown Phase One: mail.openjdk.org/pipermail/jd... openjdk.org/projects/jdk... #JDK25 #OpenJDK #Java
JDK 25 is now in Rampdown Phase One
mail.openjdk.org
It’s 5 days left to JavaOne. Go buy a ticket if you haven’t already! And don’t miss my session about what we are cooking in the ZGC project right now: reg.rf.oracle.com/flow/oracle/...
Session Catalog
reg.rf.oracle.com
#Java developers! @JavaOne is BACK (18-20 Mar). Early bird registration is available through Feb 9th. Please (re)join us at THE conference that started it all... Blog ➡️ social.ora.cl/6015Qne5z Event ➡️ javaone.com #JavaOne #OpenJDK #JDK
I used to have a bunch of followers on here. Now I can’t find them any more; it just says 404.
Looks like Cassandra is getting support for JDK 21 and decided to switch GC to Generational ZGC. Good choice! I like how GC pause warning threshold changed from 1 second to 10 ms and logging threshold from 200 ms to 2 ms. PR: github.com/apache/cassa...
Add JDK21 support by jmckenzie-dev · Pull Request #3696 · apache/cassandra
Add JDK21 support Patch by jmckenzie; reviewed by TBD for CASSANDRA-18831
github.com
I finally deactivated my ”X” account after a long time of not using it. I simply don’t want to go back there.
I migrated to bluesky rather early. Why? Because I know garbage when I see it.
Helidon 4.1.4 is out now! This release contains important bugfixes and enhancements and is recommended for all users of Helidon 4. github.com/helidon-io/h...
My work on ZGC automatic heap sizing is coming together beautifully. I’m increasingly happy with the GC logs. Feeling optimistic that it can beat carefully tuned manual heap sizing. A static heap size just can’t deal with dynamic behaviour shifts as well; it’s not in its nature.
Twitter was a good ride. Hard to leave 65K followers behind, but hard to stay there too. Let's try things where the sky is blue!
My JVMLS presentation about automatic heap sizing for ZGC is now available. It’s going to be pretty cool I think. youtube.com/watch?v=wcEN...
YouTube
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NASA Discovers Potential Life On Mars After Giant Eyeball In Middle Of Planet Looks Directly Into Telescope theonion.com/nasa-discove...
Finally Java 23 is out - the first release where Generational ZGC is the default mode of ZGC!
Sharat (Shar) Chander - 🟦🌊@sharatchander.bsky.social · 2y ago#Java 23 is now available! Your: FREE, Multi-Platform, Production-Ready, Open Source, Binary Release ...made available by Oracle. Learn more: blogs.oracle.com/java/post/th... #Java23 #JDK23 #OpenJDK #JDK
#Java developers...The fifth recording from the 14th #JVM Language Summit is now available "#Valhallla - Where Are We?" by Brian Goetz (from the Java & #OpenJDK Team at #Oracle). Click to view ➡️ youtu.be/IF9l8fYfSnI?... #JVMLS #JVMLS2024
I have worked a lot on automatic heap sizing for ZGC lately (cf. openjdk.org/jeps/8329758). If you find this interesting, I will talk about it at JVMLS this year. See you there!
openjdk.org
"In fact, we’ve found for our services and architecture that there is no such trade off. For a given CPU utilization target, ZGC improves both average and P99 latencies with equal or better CPU utilization when compared to G1." writes Netflix' Danny Thomas: netflixtechblog.com/bending-paus...
Bending pause times to your will with Generational ZGC
The surprising and not so surprising benefits of generations in the Z Garbage Collector.
netflixtechblog.com
I ran in to Danny Thomas from Netflix at JVMLS last year. Told him they should try Generational ZGC. They did, and it performed very well. Now they have changed default GC to Generational ZGC at Netflix, and Danny wrote a blog post about their experience: netflixtechblog.com/bending-paus...
I try to remove a lot of unnecessary complicated code before adding a lot of complicated code. I think of it as limiting myself to a “complexity budget”. Now I’m at the point of the cycle where it’s time to add complicated code.
