Clarifying some things

All OpenJDK distributions are not created equal

Simon Ritter
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Oracle’s change to the release cadence had many users deciding to switch to OpenJDK binaries. What can Zulu bring to the table of JDK alternatives? Simon Ritter goes over some of Zulu’s features.

Azul Systems business has always been purely about Java.  Initially building processors and hardware to improve Java performance we moved to the software only Zing low-latency, high-throughput JVM almost a decade ago.  In 2013, we launched Zulu, a binary distribution of the open-source OpenJDK project to give users an alternative platform on which to run their Java applications.

When Zulu was launched, adoption took off slowly.  This was understandable because the vast majority of Java users were happy with the Oracle JDK with its regular release of free updates.  Eighteen months ago things in the world of Java went through a number of significant changes.  The decision was made to have a faster, more predictable six-month release cadence for OpenJDK.  We’ve seen JDK 10 and 11 launched last year, and it is a matter of hours for JDK 12 to be released.

A consequence of this was Oracle’s decision to switch to a long-term support (LTS) strategy; only one release every three years (starting with JDK 11) would have the extended support users were accustomed to.  To make the decision about which version of the JDK even more complicated, the license of the Oracle JDK 11 was changed so that a commercial support contract is required to use it in production.  This is the end of free updates to Java from Oracle unless you are prepared to upgrade your JDK every six months.

The impact of this has been many users deciding to switch to OpenJDK binaries.  There are several choices for this, of which Zulu is one.  Zulu comes in two flavours: Zulu Community Edition, a completely free version, and Zulu Enterprise Edition that is backed by full commercial support.

Since Oracle has announced these changes, we’ve seen massive growth in interest, downloads, and adoption of Zulu as a Java runtime.  To make Zulu even more appealing, Azul has recently made changes to the included features and to the levels of support that are offered.  Azul has also added a new certification for Zulu Enterprise.

Azul has added new features to enable free and easy monitoring of both JVM and application performance:

  • Zulu Flight Recorder is functionality that is built into the JVM that allows low-level and fine-grained metrics to be collected. Flight Recorder was an Oracle JDK only commercial feature until the release of JDK 11 when it was contributed to the OpenJDK project.  Azul has taken this feature and backported it to Zulu JDK 8.  As such, it is free for use in development, testing, and production.  Zulu Flight Recorder makes use of much of the data already gathered by the JVM for normal operations.  By doing so, it has minimal overhead (typically less that one percent) and is ideal for use in production systems.
  • Zulu Mission Control is a separate download to the Zulu JDK. This is a graphical tool that allows administrators to monitor Flight Recorder enabled JVMs in real-time or analyse recordings made during the run of an application.  Powerful features in Zulu Mission Control provide clear insights into memory usage, garbage collection events as well as thread activity.  It is even possible to trace individual methods.

To enhance the levels of support offered, Azul has added a new higher level for customers who need faster access to updates to the JDK.

As part of Zulu Enterprise, Azul offers a Service Level Agreement (SLA) for the delivery of security vulnerability fixes; those with an identified Common Vulnerability and Exposure (CVE) score.  The existing Premium level of support guarantees the release of these fixes within seven days of them being available in the current OpenJDK repository.  The new Platinum level of support brings this SLA down to an industry-leading 48 hours.

SEE ALSO: What if you released a JDK and nobody used it?

Zulu Enterprise now has open source license non-contamination certification and indemnification. Zulu Enterprise binaries are verified through detailed license analysis of all source code used to build the product (both static and dynamically generated).  Users are assured that running their applications on Zulu Enterprise will not incur a risk of license contamination or apply copyleft provisions to their code.  Azul provides indemnification against such contamination, as well as indemnification from third-party intellectual property claims.

As you can see, Zulu from Azul delivers a stable, secure platform on which to run your Java applications.  Are you ready to give it a try?


Simon Ritter

Simon Ritter is the Deputy CTO of Azul Systems. Simon has been in the IT business since 1984 and holds a Bachelor of Science degree in Physics from Brunel University in the U.K.
Simon joined Sun Microsystems in 1996 and started working with Java technology from JDK 1.0; he has spent time working in both Java development and consultancy. Having moved to Oracle as part of the Sun acquisition, he managed the Java Evangelism team for the core Java platform, Java for client applications and embedded Java. Now at Azul, he continues to help people understand Java as well as Azul’s JVM technologies and products. Simon has twice been awarded Java Rockstar status at JavaOne and is a Java Champion. He currently represents Azul on the JCP Executive Committee and on the Java SE Expert Group (JSR 379, 383 and 384).

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