What Does This Do

Adds JavaVirtualMachine.isZulu8() and extends the @Flaky condition on LogInjectionSmokeTest.check raw file injection to include Zulu 8 alongside IBM 8 and Oracle JDK 8.

Motivation

CI Visibility data for the last 30 days shows 23 failures of check raw file injection on master, all 100% on Zulu 8 (1.8.0_482 and 1.8.0_492). Failure mode: logLines.size() == 7 got 3. Spread evenly across the three JUL→Log4j2 backend variants (JULInterfaceLog4j2{Backend,BackendNoTags,LatestBackend}).

Root cause analysis: a JDK 8 race between java.util.logging.LogManager.<clinit> and ClassLoader.initSystemClassLoader() when something during agent premain triggers LogManager class loading. On Zulu 8 the trigger is the backported JFR's use of java.util.logging from premain code paths. The agent's existing waitForJUL guard at Agent.java:382-396 mitigates this most of the time, but leaks at ~0.25% — when the leak fires, the user's -Djava.util.logging.manager property is silently ignored and JUL falls back to the default LogManager, so subsequent Logger.info(...) calls don't reach Log4j2's appenders.

The same failure mode already justifies @Flaky on Oracle JDK 8 (same JFR backport) and IBM 8 (where OkHttp transitively loads IBMSASL → JUL); Zulu 8 belongs alongside them.

Additional Notes

• This suppresses the flaky CI signal but does NOT fix the underlying agent race. Real-world Zulu 8 users running with a custom LogManager (Log4j2 JUL bridge, JBoss LogManager, etc.) plus dd-java-agent still experience the same intermittent JUL routing loss. A proper fix in Agent.java (e.g. pre-initializing LogManager early in premain, or fully deferring OkHttp/network init out of premain) should follow up.
• Local repro attempts (1000 iter Mac arm64) and CI repro attempts (~140 gradle iter + 300 direct-JVM iter) did NOT capture the failure — bug rate is too low to reliably hit. Diagnosis is from CI Visibility statistical data + agent code analysis (Agent.java:376-379 explicitly documents this race) + JDK 8 source review of LogManager.<clinit> and ClassLoader.initSystemClassLoader().

Contributor Checklist

• Format the title according to the contribution guidelines
• Assign the type: and (comp: or inst:) labels — type: bug, comp: logging, tag: ai generated, tag: no release notes
• Avoid using close, fix, or any linking keywords when referencing an issue
• Update the CODEOWNERS file on source file addition, migration, or deletion — N/A (no file additions)
• Update public documentation with any new configuration flags or behaviors — N/A (test-only change)

Jira ticket: N/A