Java used by TeamCity server is not updating

Symptoms

A new Java version is installed on the TeamCity server machine. The JAVA_HOME environment variable points to this new version, and the path to the Java bin is added to the PATH environment variable. Executing java -version in the command line shows the new version.

However, the TeamCity server still uses the old version of Java when starting.

Cause

Most probably, the <TeamCity Home>/jre directory exists, and Java found in this directory is being used.

When this directory exists, it will always be used over the JDK/JRE pointed to by JAVA_HOME. How TeamCity selects the Java to run the server process is described in the documentation:

TeamCity selects the Java version to run the server process as follows:

• By default, if your TeamCity installation has a bundled JRE (the <TeamCity Home>/jre directory exists), it will be used to run the TeamCity server process. To use a different JRE, specify its path via the TEAMCITY_JRE environment variable.
• If there is no <TeamCity Home>/jre directory present, TeamCity looks for the JRE_HOME or JAVA_HOME environment variable pointing to the installation directory of JRE or JVM (Java SDK) respectively. If both variables are declared, JRE will be used.

Resolution

To use the JRE outside of <TeamCity Home>/jre, specify its path via the TEAMCITY_JRE environment variable. Alternatively, it is possible to copy the contents of the JAVA_HOME directory to <TeamCity Home>/jre:

If your TeamCity installation has a bundled JRE (there is the <TeamCity Home>\jre directory), update it by installing a newer JRE per installation instructions and copying the content of the resulting directory to replace the content of the existing <TeamCity Home>\jre directory.