`ActiveSessionException` in TestNG integration suggests conflict with parallel execution

A user running TestNG tests with the appmap-java agent is encountering an ActiveSessionException, which causes the recording to fail. We suspect this is due to TestNG's parallel execution feature, which the AppMap agent's Recorder may not currently support.

When multiple tests run concurrently, each test thread appears to trigger the AppMap TestNG hook (com.appland.appmap.process.hooks.test.TestNG.testng) and attempts to call startRecording. The first test succeeds, but subsequent concurrent tests fail when the Recorder detects that a session is already active, throwing the exception.

Error Log & Stack Trace

The key error message from the user's log is:

AppMap agent version 1.28.0 starting
[TestNG] Running:
  <path-to-project>\src\test\resources\testsuite\testing.xml
...
17:08:07.398 [main] WARN RecordingSupport.startRecording: com.appland.appmap.record.ActiveSessionException: an active recording session already exists
    at com.appland.appmap.record.Recorder$ActiveSession.set(Recorder.java:162)
    at com.appland.appmap.record.Recorder.start(Recorder.java:241)
    at com.appland.appmap.process.hooks.RecordingSupport.startRecording(RecordingSupport.java:59)
    at com.appland.appmap.process.hooks.test.TestSupport.startRecording(TestSupport.java:63)
    at com.appland.appmap.process.hooks.test.TestSupport.startRecording(TestSupport.java:25)
    at com.appland.appmap.process.hooks.test.TestNG.testng(TestNG.java:45)

Requested Action

1. Investigate: Please confirm if appmap-java's TestNG support is compatible with parallel test execution (e.g., parallel="methods" or parallel="tests" in the testng.xml suite).
2. Remediate:
   • Ideally: If possible, update the agent to properly support parallel TestNG execution, perhaps by managing recording sessions on a per-thread basis.
   • Alternatively: If parallel support is not feasible or as an interim solution, please add logic to detect when TestNG parallelism is enabled and automatically disable it (force serial execution) when the AppMap agent is attached. This would prevent the crash and allow users to generate AppMaps, albeit with a slower test run.

Full Terminal Output (for context)

"<path-to-java>\bin\java.exe" -ea -Didea.test.cyclic.buffer.size=1048576 -Dappmap.config.file=<path-to-project>\appmap.yml -javaagent:<user-home>\.appmap\lib\java\appmap.jar "-javaagent:<path-to-ide>\lib\idea_rt.jar=56911" -javaagent:<user-home>\AppData\Local\JetBrains\IdeaIC\captureAgent\debugger-agent.jar -Dkotlinx.coroutines.debug.enable.creation.stack.trace=false -Ddebugger.agent.enable.coroutines=true
 -Dkotlinx.coroutines.debug.enable.flows.stack.trace=true -Dkotlinx.coroutines.debug.enable.mutable.state.flows.stack.trace=true -Dfile.encoding=UTF-8 @<temp-path>\idea_arg_file1573352798 com.intellij.rt.testng.RemoteTestNGStarter -usedefaultlisteners
 false -socket56910 @w@<temp-path>\idea_working_dirs_testng2.tmp -temp <temp-path>\idea_testng2.tmp

AppMap agent version 1.28.0 starting

[TestNG] Running:

  <path-to-project>\src\test\resources\testsuite\testing.xml
Java HotSpot(TM) 64-Bit Server VM warning: Sharing 
is only supported for boot loader classes because bootstrap classpath 
has been appended

SLF4J(W): No SLF4J providers were found.
.. 
17:08:07.398 [main] WARN RecordingSupport.startRecording: com.appland.appmap.record.ActiveSessionException: an active recording session already exists

    at com.appland.appmap.record.Recorder$ActiveSession.set(Recorder.java:162)

    at com.appland.appmap.record.Recorder.start(Recorder.java:241)

    at com.appland.appmap.process.hooks.RecordingSupport.startRecording(RecordingSupport.java:59)

    at com.appland.appmap.process.hooks.test.TestSupport.startRecording(TestSupport.java:63)

    at com.appland.appmap.process.hooks.test.TestSupport.startRecording(TestSupport.java:25)

    at com.appland.appmap.process.hooks.test.TestNG.testng(TestNG.java:45)

com.appland.appmap.process.hooks.test.TestNG.testng とスタックトレースに示されている Recorder.start のパスから始め、次に RecordingSupport.startRecording と TestSupport.startRecording を調べます。TestNG parallel="methods" または parallel="tests" で失敗を再現し、セッションをスレッドごとに分離できるか、または並列実行を無効にする必要があるかを判断します。並列実行によって ActiveSessionException が発生しなくなり、記録も引き続き完了すれば完了です。