JDK Flight Recorder introduced in OpenJDK 11.
This feature is low overhead of profiling and be able to used on production environment.
High Performance recording engine is embedded to Hotspot VM.
GraalVM を普通の Java VM として使う ~クラウドベンチマークなどでの比較~Shinji Takao
クラウドや多言語の環境に対応できる 新しいJava実行環境 GraalVM は、ネイティブビルドだけでなく、通常の Java VM として使うこともできます。
このたび、クラウド環境用ベンチマーク「BluePerf」などを使い、GraalVM と OpenJDK を比較したので、結果を報告します。
Japan Java User Group (JJUG) Cross Community Conference (CCC) 2021 Fall 発表資料
https://www.youtube.com/watch?v=5MtjfQfdC_g
Java 女子部 講義資料
https://javajo.doorkeeper.jp/events/21337
This presentation is used to lecture about the introduction of Java Virtual Machine at Java Japan User Group (Girls).
Java 女子部 講義資料
https://javajo.doorkeeper.jp/events/21337
This presentation is used to lecture about the introduction of Java Virtual Machine at Java Japan User Group (Girls).
Way Improved :) GC Tuning Confessions - presented at JavaOne2015Monica Beckwith
This document provides a summary of a presentation on GC tuning confessions of a performance engineer. It begins with introductions of the speaker and an overview of topics to be covered, including performance engineering, insight into garbage collectors, OpenJDK HotSpot GCs, GC algorithms, key topics, and GC tunables. The document then goes into more detail on various GC algorithms like Parallel GC, CMS GC, and G1 GC. It discusses concepts like promotion failures, concurrent mode failures, incremental compaction, and fragmentation. It also provides examples and explanations of various GC-related log entries.
Garbage First Garbage Collector (G1 GC) - Migration to, Expectations and Adva...Monica Beckwith
Learn what you need to know to experience nirvana in the evaluation of G1 GC even if your are migrating from Parallel GC to G1, or CMS GC to G1 GC
You also get a walk through of some case study data
G1 GC
Java Concurrency, A(nother) Peek Under the Hood [Java Day Tokyo 2016 3-C]David Buck
去年のJJUGナイトセミナー JVM特集で実施した「HotSpot のロック: A Peek Under the Hood」の続きのセッションです。
java.util.concurrentやJava Memory Modelの実装について、いくつかご紹介します。これらで不可欠な技術がJVMとクラス・ライブラリでどのように提供されているかを簡単に説明します。たとえば、volatileキーワードの利用時に、JITコンパイルによって生成されるコードはどのように変わるかを分析します。
Head toward Java 14 and Java 15 #LINE_DMYuji Kubota
Java 14 and 15 introduced several new features and changes including records, pattern matching, text blocks, and updates to the garbage collector. Some notable changes were the addition of records as a new data type, enabling pattern matching for instanceof, and deprecating biased locking and the CMS garbage collector. Tools were also improved with the packaging tool to create installers and event streaming to collect JVM events.
This document discusses new features and changes in Java 14 and previews for Java 15. For Java 14, it outlines 16 JEPs including helpful null pointer exceptions, NUMA-aware memory allocation, and removing legacy garbage collectors. It also covers new tools like JFR event streaming and the packaging tool. For Java 15, hidden classes, removing Nashorn, and low-latency garbage collectors like ZGC and Shenandoah are previewed. Overall it provides a concise yet informative summary of major changes and previews for Java 14 and 15.
JavaOne 2017 報告会 at Japan Java User Group
デモのコード:https://github.com/ykubota/jigsaw-sample_jp
イベントページ:https://jjug.doorkeeper.jp/events/66256
Stream: https://www.youtube.com/watch?v=XT2tIh9r6Eo
slideshareが自動的にPDFに変換するように仕様変更されていたため、ノート付きでアップロードができませんでした。お手数をおかけしますが、原稿(簡単ですが…)を読んでみたい方は筆者までTwitterでDMかメールなどでご連絡お願いします。
Secrets of Rock Star Developers (and How to Become One!) [CON7615] (Yuji KUBO...Yuji Kubota
Kubota Yuji is a Java technical support engineer at NTT and a hard-of-hearing open source developer. He recommends reading code and writing code through trial and error. Maintaining documentation and comments is important to help others. Conversation through chat, mailing lists, and tweets from conferences help hard-of-hearing developers. Written knowledge from articles and books also provide assistance, as do watching sessions on YouTube with subtitles. Attending JUGs can introduce developers to professionals. With helpful accessibility options and kind communities, hard-of-hearing people need not give up on becoming good developers.
The document discusses using jcmd to troubleshoot Java applications. It provides an overview of the jcmd command and describes the various domains and suffixes that can be used with jcmd to obtain diagnostic information or control the JVM. These include getting thread dumps, heap details, JIT compiler data, and configuring Java logging. The document also demonstrates some example jcmd commands.
JavaOne 2016 Java SE Feedback #jjug #j1jpYuji Kubota
Slide for reporting Java SE Feedback of JavaOne 2016 at Japan Java User Group. Especially, this slide introduces the changes required for Java 9.
https://jjug.doorkeeper.jp/events/52639
11. Copyright(c)2014 NTT Corp. All Rights Reserved. 10
Native
Metaspace
Java heapPermanentnative
Thread
Stack
-Xmx-XX:MaxPermSize
OS
-Xss*threads
Compressed Class
Space
JDK7以前
JDK8
-XX:MaxMetaspaceSize-XX:CompressedClassSpaceSize
14. Copyright(c)2014 NTT Corp. All Rights Reserved. 13
Metaspace
Java heapPermanentnative
Thread
Stack
-Xmx-XX:MaxPermSize
OS
-Xss*threads
Compressed Class
Space
JDK7以前
JDK8
heap + non-heap
-XX:MaxMetaspaceSize-XX:CompressedClassSpaceSize
17. Copyright(c)2014 NTT Corp. All Rights Reserved. 16
Metaspace
Java heapPermanentnative
Thread
Stack
-Xmx-XX:MaxPermSize
OS
-Xss*threads
Compressed Class
Space
JDK7以前
JDK8
non-heap
-XX:MaxMetaspaceSize-XX:CompressedClassSpaceSize
20. Copyright(c)2014 NTT Corp. All Rights Reserved. 19
Metaspace
Java heapPermanentnative
Thread
Stack
-Xmx-XX:MaxPermSize
OS
-Xss*threads
Compressed Class
Space
JDK7以前
JDK8
heap
-XX:MaxMetaspaceSize-XX:CompressedClassSpaceSize