Java

→ Heap dump

The jcmd tool produce a binary heap dump

jcmd <pid> GC.heap_dump <file-path>

The below option does not add overhead, and using it in production is a good idea.

java -XX:+HeapDumpOnOutOfMemoryError -XX:HeapDumpPath=<file-or-dir-path>

Eclipse Memory Annalyser allows to analyse the resulting dump files. this tutorial explains well how to use the tool.

Building Microservices: Designing Fine-Grained Systems, Second Edition (O’Reilly Media, 2021)
Microservices Patterns by Chris Richardson (Manning, 2018)

MAVEN_OPTS='-Dorg.slf4j.simpleLogger.defaultLogLevel=error' mvn test

mvn versions:set -DgroupId=* -DartifactId=* -DnewVersion=0.13.0 -DgenerateBackupPoms=false

A Java virtual machine (JVM) is an abstract machine. It is a specification that provides a runtime environment in which Java bytecode can be executed.
The Java Runtime Environment (JRE) is used to provide a runtime environment. It is the implementation of the JVM that physically exists. It contains a set of libraries and other files that the JVM uses at runtime. Oracle bought Sun Microsystems in 2010; since then, new versions and patches have been actively provided. Other companies, such as IBM, provide their own implementations of the JVM.
The Java Development Kit (JDK) contains the JRE, documentation, and Java tools. This is what Java developers install on their machines. A smart editor like IntelliJ IDEA or Eclipse will require you to provide the location of the JDK so classes and documentation can be loaded and used during development.

Java Management Extensions (JMX) framework
jmx tutorial
visualVM is a jdk tool to explore jmx metrics of the application running in the respective jvm

This page was last modified: 2024-10-01 00:40