Episode notes
The Java tool jcmd ("j command") sends diagnostic commands to the JVM, which will react by supplying the desired information: from finalizer queues to heap and thread dumps, from GC insights to virtual thread scheduler statistics. At the moment, this requires a running JVM, but once candidate JEP 528 is adopted, a lot of that information can be seamlessly extracted from a crashed JVM's core dump, allowing easy post-mortem analysis.
Inside Java
by David Delabassee · English · Tech & Science
Inside Java is a podcast for Java Developers brought to you directly from the people that make Java at Oracle. We'll discuss the language, the JVM, OpenJDK, platform security, innovation projects like Loom and Panama, and everything in between.
More from Inside Java
-
S3 · E11 · 23 Apr 2026 · 58 min
"Ask the Architects at JavaOne'26" [AtA]
In JavaOne 2026's closing session, audience members had the opportunity to ask the Java architects questions. They asked about the state of structured concurrency and Project Babylon, how Java is being developed and the role AI plays in that process, the architects' pet projects, and whether they would ever consider breaking backward compatibility, etc. Make sure to check https://inside.java/podcast
-
S3 · E10 · 16 Apr 2026 · 10 min
"You Must Avoid Final Field Mutation" [IJN]
With JDK 26 / JEP 500 starting to prevent final field mutation through reflection, it is important that Java projects stop employing that practice. For more, check https://inside.java/podcast
-
S3 · E9 · 9 Apr 2026 · 17 min
"How JDK 26 Improves G1's Throughput" [AtA]
G1 is Java's default garbage collector in most environments, and its throughput has been considerably improved in JDK 26 by streamlining its write barriers. This conversation explores the background of that change and dives deep into regions, write barriers, concurrent marking, card tables, and how all that impacts throughput before eventually getting to the improvements made in Java 26, which lay further groundwork to G1 becoming the one and only default collector across _all_ environments. In this "Ask the Architect" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai…
-
S3 · E8 · 26 Mar 2026 · 46 min
"Java Carrier Classes & Discussing Syntax" [AtA]
Carrier classes are Project Amber's current idea to extend some of records' benefits to regular classes. Probably the most important among them is deconstruction, which would allow classes to participate in pattern matching and reconstruction. In recent weeks, there have been two mails to the Amber mailing list that describe that idea, and in this episode we discuss them both as well as the evolution between them. We also hear why syntax discussions often provide negative value and get a sneak peak at what will likely be the next Project Amber language feature. Just ahead of the JavaOne…
-
S3 · E7 · 12 Mar 2026 · 11 min
"Unboxing Java 26 for Developers" [IJN]
Java 26 is getting all packaged up to be shipped worldwide! As with every release of the JDK there are a number of new features, improvements, changes in behavior, and more developers should be aware of before upgrading. In this episode of the Inside Java Newscast we will review all the noteworthy changes coming in Java 26 that will impact developers.
-
S3 · E6 · 9 Mar 2026 · 13 min
"Towards Better Checked Exceptions" [IJN]
Java's checked exceptions are both an integral part of the language and one of its most contested features. Whether their introduction was a mistake and whether they should all be turned unchecked are frequently discussed topics but since the former is not overly relevant and the latter unlikely, this conversation isn't moving Java forward. Instead, let's talk about specific issues with checked exceptions and what could be done about them - from (entirely speculative) language changes to (marginally realistic) JDK/library evolution to stylistic changes.
-
S3 · E23 · 24 Sep 2026 · 33 min
"Security in Java" [AtA]
Given how prevalent Java is on web servers throughout the internet, security in Java is of critical importance. There's the security of the JDK itself, of course, which is overseen by the OpenJDK Security Group, which you should report JDK vulnerabilities to. But there are also the algorithms and features Java offers applications that are built on top of it and the cryptographic road map is an essential part of that development process. In recent years, post-quantum encryption has made big splashes but Java now also supports PEM texts and is considering the adoption of Argon2. In this "Ask…
-
S3 · E22 · 17 Sep 2026 · 1 hr 11 min
"AOT Caching - Netflix' Practice vs OpenJDK's Theory" [I/O]
Java projects that want to reduce their launch times need to look into Java's new ahead-of-time capabilities. A training run is used to populate a cache that, in production, allows the JVM to short-circuit many operations, like class loading and linking, profile gathering, and - probably soon - JIT compilation. To get the most out this feature, a good training run is essential. Netflix approach is pretty much the ideal one: use a canary deployment of a new version to collect training data and create the cache for the remaining deployments from that. But, from time scales to checkpointing,…
-
S3 · E21 · 10 Sep 2026 · 16 min
"Declassifying the Java 27 Release!" [IJN]
Java 27 is heading for release on September 15th. As with every release of the JDK there are a host of changes that will impact developers, from new features, to changes in behavior of existing features. In this episode of the Inside Java Newscast we will be "declassifying" all the developer impacting changes in Java 27.
-
S3 · E20 · 27 Aug 2026 · 42 min
"Operator Overloading with Type Classes" [AtA]
OpenJDK's Project Valhalla is improving Java's support for custom numerical types. That goes beyond value types and also encompasses explorations into operator support. While Java is extremely unlikely to ever allow arbitrary operator definitions, it may well support limited operator overloading, so custom value types could be added or multiplied with plus or multiplication signs instead of annoying method calls. In this "Ask the Architects" episode of the Inside Java Podcast, recorded during JavaOne 2026, Nicolai Parlog talks to Joe Darcy, Valhalla committer in the Java Platform Group at…
