detachCurrentThreadFromJvm: Unable to detach thread %s from

Error message

detachCurrentThreadFromJvm: Unable to detach thread %s from the JVM. Error code: %d

What it means

Windows TLS destructor: DetachCurrentThread returned a value other than JNI_OK (e.g. JNI_EDETACHED, the thread was not attached). The thread id string is fetched via the JVM for context, then the state is freed. Teardown-time warning; no data is lost beyond the log line.

Source

Thrown at hadoop-hdfs-project/hadoop-hdfs-native-client/src/main/native/libhdfs/os/windows/thread_local_storage.c:66

  }
  env = state->env;
  if ((env == NULL) || (*env == NULL)) {
    return;
  }
  ret = (*env)->GetJavaVM(env, &vm);
  if (ret) {
    fprintf(stderr,
      "detachCurrentThreadFromJvm: GetJavaVM failed with error %d\n",
      ret);
    (*env)->ExceptionDescribe(env);
  } else {
    ret = (*vm)->DetachCurrentThread(vm);

    if (ret != JNI_OK) {
      (*env)->ExceptionDescribe(env);
      get_current_thread_id(env, thr_name, MAXTHRID);

      fprintf(stderr, "detachCurrentThreadFromJvm: Unable to detach thread %s "
          "from the JVM. Error code: %d\n", thr_name, ret);
    }
  }

  /* Free exception strings */
  if (state->lastExceptionStackTrace) free(state->lastExceptionStackTrace);
  if (state->lastExceptionRootCause) free(state->lastExceptionRootCause);

  /* Free the state itself */
  free(state);
}

static void get_current_thread_id(JNIEnv* env, char* id, int max) {
  jclass cls;
  jmethodID mth;
  jobject thr;
  jstring thr_name;
  jlong thr_id = 0;

View on GitHub (pinned to 2add963021)

Solutions

Informational at shutdown — no action unless accompanied by failures
If recurring mid-run, audit double-detach sources in-process
Keep HDFS calls off threads during teardown

Defensive patterns

Strategy: fallback

Prevention

Prevent other JNI libraries from detaching libhdfs threads
Shut down HDFS activity before beginning teardown
Classify shutdown-only occurrences as log noise

When it happens

Trigger: Double-detach at DLL detach time; detach attempted while the JVM is being destroyed and refuses.

Common situations: Other native libraries managing attachment; exit-order races between DLL unload and JVM destruction.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/05fbbeff2826b984. Report an issue: GitHub.