Optimized to run Java™ applications cost-effectively in the cloud, Eclipse OpenJ9™ is a fast and efficient JVM that delivers power and performance when you need it most.
Optimized for the Cloud, for microservices and monoliths too!
Faster Startup
Faster Ramp-up, when deployed to cloud
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Join us on Slack where you can ask questions and chat directly with our developers. Whether you simply have a question about using OpenJ9, an idea for improvement, or a problem you want to discuss, we'd love to hear from you.
Join OpenJ9 SlackLike all great open source projects, we have a vibrant and busy GitHub repository where you can create issues to explore ideas, request new features, or report any difficulties you are having.
See OpenJ9 IssuesWe welcome contributions to the project in all shapes and forms. If you are interested in JVM development, we'd love to hear your ideas and help you collaborate with us on the code base. There are other ways you can contribute too, such as working on our website and docs. Be a part of the project and share in our success!
Contributor GuideOur regular calls are a great place to find out what is going on in the project. As well as discussing our release plans and development status, we often feature lightning talks by members of the community. For example, technical deep dives or overviews about new features. To see agendas and recordings, look in the Slack #planning channel.
Add to CalendarFebruary 2024
We're pleased to announce the availability of Eclipse OpenJ9 v0.43.0.
This release supports OpenJDK version 8, 11, 17, and 21. For more information about supported platforms and OpenJDK versions, see Supported environments.
Other updates in this release include the following:
-XX:[+|-]CRIUSecProvider
option is added to enable or disable CRIUSECProvider
during the checkpoint phase. You can choose to continue to use all the existing security providers during the checkpoint phase instead of the CRIUSECProvider
.-XX:Compatibility
option is added to enable a compatibility mode that OpenJ9 can run in to support applications that require specific capabilities. In release 0.43.0, the compatibility mode is provided for the Elasticsearch application only.-XX:[+|-]CpuLoadCompatibility
option is added to enable or disable the OpenJDK behavior of the getProcessCpuLoad()
and getSystemCpuLoad()
methods in OpenJ9 so that these methods return 0 when called in OpenJ9 for the first time. This change in the method return value makes it easier to differentiate between the first call behavior and an error that needs further investigation.com.sun.management.ThreadMXBean.getThreadAllocatedBytes()
API on z/OS® platforms.To read more about these and other changes, see the OpenJ9 user documentation.
Performance highlights include: