Q: regarding agent not being able to attach.

[lmcdasi]

Q: regarding agent not being able to attach.

[jeanbisutti]

@lmcdasi The Linux user of the JVM may not have access to /proc/7/root/tmp. Could you please check?

It does not work without -Djdk.attach.allowAttachSelf=true?

[lmcdasi]

The jvm option: -Djdk.attach.allowAttachSelf=true seems to be mandatory. I'm using MSFT openjdk:17 docker image.

Without it, I'm getting:

connector | 14:39:06.600 [main] INFO connector.Application -- ApplicationInsights enabled with file /tmp/app-insights/applicationinsights-dev.json
connector | Jan 29, 2024 2:39:06 PM com.microsoft.applicationinsights.attach.ApplicationInsights attach
connector | WARNING: Fail to runtime attach Application Insights
connector | io.opentelemetry.contrib.attach.core.RuntimeAttachException: A problem has occurred during the runtime attachment of the Java agent.
connector | at io.opentelemetry.contrib.attach.core.CoreRuntimeAttach.handleByteBuddyException(CoreRuntimeAttach.java:106)
connector | at io.opentelemetry.contrib.attach.core.CoreRuntimeAttach.attachJavaagentToCurrentJVM(CoreRuntimeAttach.java:55)
connector | at com.microsoft.applicationinsights.attach.ApplicationInsights.attach(ApplicationInsights.java:63)
connector | at connector.Application.main(Application.java:38)
media-connector | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
connector | at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
connector | at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
connector | at java.base/java.lang.reflect.Method.invoke(Method.java:568)
connector | at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:49)
connector | at org.springframework.boot.loader.Launcher.launch(Launcher.java:95)
connector | at org.springframework.boot.loader.Launcher.launch(Launcher.java:58)
connector | at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:65)
connector | Caused by: java.lang.IllegalStateException: Could not self-attach to current VM using external process
connector | at net.bytebuddy.agent.ByteBuddyAgent.installExternal(ByteBuddyAgent.java:706)
connector | at net.bytebuddy.agent.ByteBuddyAgent.install(ByteBuddyAgent.java:636)
connector | at net.bytebuddy.agent.ByteBuddyAgent.attach(ByteBuddyAgent.java:303)
connector | at net.bytebuddy.agent.ByteBuddyAgent.attach(ByteBuddyAgent.java:268)
connector | at net.bytebuddy.agent.ByteBuddyAgent.attach(ByteBuddyAgent.java:250)
connector | at io.opentelemetry.contrib.attach.core.CoreRuntimeAttach.attachJavaagentToCurrentJVM(CoreRuntimeAttach.java:53)
connector | ... 10 more

[lmcdasi]

Regarding /tmp - it seems that if I have it as a volume mounted in docker compose it affects the way it sees that java pid file. I have changed the strategy and now with the allowAttachSelf set to true there is no exception any longer.

connector | OpenJDK 64-Bit Server VM warning: Sharing is only supported for boot loader classes because bootstrap classpath has been appended
connector | 2024-01-29 14:46:57.610Z INFO c.m.applicationinsights.agent - Application Insights Java Agent 3.4.19 started successfully (PID 7, JVM running for 4.855 s)
connector | 2024-01-29 14:46:57.615Z INFO c.m.applicationinsights.agent - Java version: 17.0.10, vendor: Microsoft, home: /usr/lib/jvm/msopenjdk-17-amd64

[jeanbisutti]

Regarding /tmp - it seems that if I have it as a volume mounted in docker compose it affects the way it sees that java pid file. I have changed the strategy and now with the allowAttachSelf set to true there is no exception any longer.

Thank you for sharing this. Would you mind if you could share the code of the not working Docker compose configuration?

Does it also work now without the allowAttachSelf property? If it does not work in this case, you can display the root cause error by setting the net.bytebuddy.agent.attacher.dump property to a file path.

[lmcdasi]

Here is what is causing the issue of the self attach to fail. If in the docker-compose, I have:

  JAVA_OPTIONS: "-DAPPLICATIONINSIGHTS_ENABLED=true -Dapplicationinsights.configuration.file=/mnt/app-insights/applicationinsights-dev.json -Dnet.bytebuddy.agent.attacher.dump=/tmp/bytebuddy.dump"
  JAVA_TOOL_OPTIONS: "-agentlib:jdwp=transport=dt_socket,address=*:5006,server=y,suspend=n"

Then I will get the self attach issue. But, if I move the java_tool_options within the java options as:

  JAVA_OPTIONS: "-agentlib:jdwp=transport=dt_socket,address=*:5006,server=y,suspend=n -XX:+StartAttachListener -XX:-DisableAttachMechanism -DAPPLICATIONINSIGHTS_ENABLED=true -Dapplicationinsights.configuration.file=/mnt/app-insights/applicationinsights-dev.json -Dnet.bytebuddy.agent.attacher.dump=/tmp/bytebuddy.dump"

Then I have no issue, and that because the agent is running the Agent.class as a new java process and inherits the debugger settings ... ByteBuddyAgent.class method installExternal - if (new ProcessBuilder(System.getProperty(JAVA_HOME) ....

Thank you.