Which version of Java agent supports Java 21?

[jvissers]

When I try starting the agent (1.22.0) - on OpenJDK 21, I see this error:

Picked up JAVA_TOOL_OPTIONS: -Xdebug -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005 -javaagent:/app/libs/opentelemetry-javaagent-1.22.0.jar
2023-12-30T12:44:14.305403424Z Listening for transport dt_socket at address: 5005
2023-12-30T12:44:14.539883777Z OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
2023-12-30T12:44:14.586205249Z [otel.javaagent 2023-12-30 12:44:14:585 +0000] [main] INFO io.opentelemetry.javaagent.tooling.VersionLogger - opentelemetry-javaagent - version: 1.22.0
2023-12-30T12:44:14.768428384Z OpenTelemetry Javaagent failed to start
2023-12-30T12:44:14.768447283Z java.lang.ExceptionInInitializerError
2023-12-30T12:44:14.768448809Z 	at io.opentelemetry.javaagent.tooling.muzzle.AgentTooling.<clinit>(AgentTooling.java:22)
2023-12-30T12:44:14.768450194Z 	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:139)
2023-12-30T12:44:14.768451313Z 	at io.opentelemetry.javaagent.tooling.AgentInstaller.installBytebuddyAgent(AgentInstaller.java:94)
2023-12-30T12:44:14.768482205Z 	at io.opentelemetry.javaagent.tooling.AgentStarterImpl.start(AgentStarterImpl.java:78)
2023-12-30T12:44:14.768497315Z 	at io.opentelemetry.javaagent.bootstrap.AgentInitializer.initialize(AgentInitializer.java:35)
2023-12-30T12:44:14.768500978Z 	at io.opentelemetry.javaagent.OpenTelemetryAgent.startAgent(OpenTelemetryAgent.java:57)
2023-12-30T12:44:14.768502386Z 	at io.opentelemetry.javaagent.OpenTelemetryAgent.premain(OpenTelemetryAgent.java:45)
2023-12-30T12:44:14.768503475Z 	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
2023-12-30T12:44:14.768504554Z 	at java.base/java.lang.reflect.Method.invoke(Method.java:580)
2023-12-30T12:44:14.768505645Z 	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:560)
2023-12-30T12:44:14.768507981Z 	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:572)
2023-12-30T12:44:14.768525307Z Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final java.lang.Class java.lang.ClassLoader.findLoadedClass(java.lang.String) accessible: module java.base does not "opens java.lang" to unnamed module @7d907bac
2023-12-30T12:44:14.768532897Z 	at java.base/java.lang.reflect.AccessibleObject.throwInaccessibleObjectException(AccessibleObject.java:391)
2023-12-30T12:44:14.768540525Z 	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:367)
2023-12-30T12:44:14.768542640Z 	at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:315)
2023-12-30T12:44:14.768546598Z 	at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:203)
2023-12-30T12:44:14.768567983Z 	at java.base/java.lang.reflect.Method.setAccessible(Method.java:197)
2023-12-30T12:44:14.768580037Z 	at io.opentelemetry.javaagent.tooling.muzzle.AgentCachingPoolStrategy.getFindLoadedClassMethod(AgentCachingPoolStrategy.java:114)
2023-12-30T12:44:14.768654189Z 	at io.opentelemetry.javaagent.tooling.muzzle.AgentCachingPoolStrategy.<clinit>(AgentCachingPoolStrategy.java:57)
2023-12-30T12:44:14.768656698Z 	... 11 more`

Is there a version that supports Java 21? And if so, which one?

Thanks,
- Jan.

[laurit]

Is there a version that supports Java 21? And if so, which one?

Try the latest version of the agent. 1.22.0 is almost a year old while jdk 21 was released in 19 September 2023. As you are using an agent version that was released quite a bit before jdk 21 it isn’t too surprising that it does not work.

[jvissers]

Changing to 1.32.0 made the problem go away. Thanks.