Symptom

When starting any component of StackState, the log shows a message similar to the following:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by org.codehaus.groovy.reflection.CachedClass (file:/opt/stackstate/stackgraph/lib/groovy-2.4.8-indy.jar) to method java.lang.Object.finalize()
WARNING: Please consider reporting this to the maintainers of org.codehaus.groovy.reflection.CachedClass
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

Cause

This warning is the result of restrictions imposed by JDK 11 on certain operations.

Solution

JDK versions 9 or higher are not currently supported. See the StackState Requirements for Linux servers.