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Software Architect, Java & JVM passionate, Quarkus, like to learn stuff and share what I learnt. You can follow me on Twitter : https://twitter.com/loicmathieu
Java 17 : what’s new ?

Java 17 : what’s new ?

Now that Java 17 is features complete (Rampdown Phase Two at the day of writing), it’s time to walk throught all the functionalities that brings to us, developers, this new version. This article is part of a series on what’s new on the last versions of Java, for those who wants to read the others, here are the links : Java 16, Java 15, Java 14, Java 13, Java 12, Java 11, Java 10, and Java 9. This release doesn’t contain many JEPs,…

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Debugging a GraalVM native image with GDB

Debugging a GraalVM native image with GDB

In a previous article, I mentioned how to profile a native GraalVM image with perf. If you are not familiar with the GraalVM tool and the limitations it brings, I suggest you reread my article, or at least the beginning of it. As seen in my previous article, a native image will contain a minimalist JVM, called SubstrateVM, which does not support JVM-TI, and therefore does not allow the use of Java debuggers. To debug a native image, you therefore…

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Introduction to Quickperf

Introduction to Quickperf

QuickPerf is a test library for Java to quickly evaluate and improve the performance of your application. The great interest of Quickperf lies in the fact that this is done via unit tests, which allows, after detecting and correcting a performance problem, to have non-regression tests so that it never comes back! You can then continuously evaluate the performance of your application via your continuous integration environment! Quickperf can be used to simply measure performance characteristics, or to assert on…

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Java 16 : what’s new ?

Java 16 : what’s new ?

Now that Java 16 is features complete (Rampdown Phase Two at the day of writing), it’s time to walk throught all the functionalities that brings to us, developers, this new version. This article is part of a series on what’s new on the last versions of Java, for those who wants to read the others, here are the links : Java 15,, Java 14, Java 13, Java 12, Java 11, Java 10, and Java 9. This new version counts no less than 17…

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Benchmark : conversion from long to byte[]

Benchmark : conversion from long to byte[]

I’ve been using Kafka a lot lately, and in Kafka a lot of things are byte arrays, even headers! As I have many components that exchange messages, I added headers to help with message tracking, including a timestamp header which has the value System.currentTimeMillis(). So I had to transform a long into a byte array; in a very naive way, I coded this: String.valueOf(System.currentTimeMillis()).getBytes(). But instantiating a String each time a header is created does not seem very optimal to…

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Profiling a GraalVM native image with perf

Profiling a GraalVM native image with perf

The GraalVM native-image tool allows you to generate a native executable (or native image) from your Java application. This native executable will start very quickly and have a much smaller memory footprint than a traditional Java application; at the cost of reduced peak performance and a relatively high packaging build time. More information on native executables here. A native executable contains a minimalist JVM called SubstratVM, this one has some limitations: Partial support for reflection Partial support for dynamic proxy…

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Java 15 : what’s new ?

Java 15 : what’s new ?

Now that Java 15 is features complete (Rampdown Phase One at the day of writing), it’s time to walk throught all it’s functionalities that brings to us, developers, this new version. This article is part of a series on what’s new on the last versions of Java, for those who wants to read the others, here are the links : Java 14, Java 13, Java 12, Java 11, Java 10, and Java 9. This new version brings lots of new JEPs, the main…

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Quarkus, jlink and Application Class Data Sharing (AppCDS)

Quarkus, jlink and Application Class Data Sharing (AppCDS)

Quarkus is optimized to start quickly and have a very small memory footprint. This is true when deploying in a standard JVM but even more so when deploying our application as a native executable via GraalVM. Quarkus greatly facilitates the creation of a native executable, thanks to this, a Quarkus application starts in a few tens of milliseconds and with a very small memory footprint: a few tens of MB of RSS (Resident Set Size – total memory usage of…

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