After ugrading Java to JDK 11, Jenkins fails to start due to Unrecognized VM option

Article ID:4569312535195
2 minute readKnowledge base

Issue

  • After upgrading to JDK 11, Operations Center and/or Controllers fail to start with an issue like the following:

      Unrecognized VM option '<JVM OPTION>'
  Error: Could not create the Java Virtual Machine.
  Error: A fatal exception has occurred. Program will exit.

Environment

Explanation

Java 11 (and mainly Java 9) removes support for many Java options:

When upgrading from Java 8 to Java 9+, unsupported and deprecated options must be removed and if possible replaced.

See CloudBees Supported Java Version for information about Java Versions support.

Resolution

Many of the previously recommended JDK 8 GC logging arguments are no longer supported:

  • -Xloggc:${LOGDIR}/gc.log / -Xloggc:${LOGDIR}/gc-%t.log

  • -XX:NumberOfGCLogFiles=2

  • -XX:+UseGCLogFileRotation

  • -XX:GCLogFileSize=100m

  • -XX:+PrintGC

  • -XX:+PrintGCDateStamps

  • -XX:+PrintGCDetails

  • -XX:+PrintHeapAtGC

  • -XX:+PrintGCCause

  • -XX:+PrintTenuringDistribution

  • -XX:+PrintReferenceGC

  • -XX:+PrintAdaptiveSizePolicy

They must be replaced by the single -Xlog argument as documented in Prepare CloudBees CI for Support:

  • -Xlog:gc*=info,gc+heap=debug,gc+ref*=debug,gc+ergo*=trace,gc+age*=trace:file=${LOGDIR}/gc.log:utctime,pid,level,tags:filecount=2,filesize=100M

Where:

  • filecount=2 is the equivalent of the deprecated -XX:NumberOfGCLogFiles=2

  • filesize=100M is the equivalent of the deprecated -XX:GCLogFileSize=100m

  • file=${LOGDIR}/gc.log / file=${LOGDIR}/gc-%t.log is the equivalent of the deprecated -Xloggc:${LOGDIR}/gc.log / -Xloggc:${LOGDIR}/gc-%t.log

  • ${LOGDIR} is an existing directory where operations center or controller can write log files, e.g. /var/log/cloudbees-core-cm

See also Java 11: Convert GC Logging Flags to Xlog and Java 11: Enable Logging with the JVM Unified Logging Framework for more details.

*Note: If the unsupported arguments is not among the one listed above, have a look at the following documentations to understand if it may simply be removed or what it may be replaced with:

This article is part of our Knowledge Base and is provided for guidance-based purposes only. The solutions or workarounds described here are not officially supported by CloudBees and may not be applicable in all environments. Use at your own discretion, and test changes in a safe environment before applying them to production systems.