ObservationAwareSpanThreadLocalAccessor does not remove SpanAction

[stalinone]

Hi, I'm using Spring Boot 3.0.9 (w/ Micrometer Tracing 1.0.8) and configured to allow trace continued when @Async method or taskExecutor#execute is called.

I noticed ObservationAwareSpanThreadLocalAccessor#spanActions map is get bigger and bigger throughout time. It seems to me that SpanAction is still persisted in the map even if the Thread is already finished.

My configuration:

@Configuration
public class Config {

    @Autowired
    public Config(Tracer tracer) {
        ContextRegistry.getInstance()
                       .registerThreadLocalAccessor(new ObservationAwareSpanThreadLocalAccessor(tracer));
    }
    

    @Bean
    public ThreadPoolTaskExecutor someExecutor() {
        final ThreadPoolTaskExecutor taskExecutor =
                new TaskExecutorBuilder()/*...*/
                         .taskDecorator(runnable -> ContextSnapshot.captureAll(new Object[0]).wrap(runnable))
                         .build();
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return taskExecutor;
    }
}

I'd like to know if there is additional configuration needs to be set, or is this a memory leak?

[stalinone]

Also, when I checking the issue that leads to adding spanActions field, I found the below configuration could achieve trace continuity without using ObservationAwareSpanThreadLocalAccessor (at least it seems):

@Configuration
public class Config {

    private final ContextSnapshotFactory contextSnapshotFactory;

    @Autowired
    public Config(ObservationRegistry observationRegistry) {
        ObservationThreadLocalAccessor.getInstance()
                                      .setObservationRegistry(observationRegistry);
        contextSnapshotFactory = ContextSnapshotFactory.builder()
                                                       .contextRegistry(ContextRegistry.getInstance())
                                                       .clearMissing(true)
                                                       .build();
    }
    

    @Bean
    public ThreadPoolTaskExecutor someExecutor() {
        final ThreadPoolTaskExecutor taskExecutor =
                new TaskExecutorBuilder()/*...*/
                         .taskDecorator(runnable -> contextSnapshotFactory.captureAll(new Object[0]).wrap(runnable))
                         .build();
        taskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        return taskExecutor;
    }
}

I'm not sure if this is a proper approach, or which one should be the suggested approach?

[marcingrzejszczak]

ObservationAwareSpanThreadLocalAccessor should be only attached if you want to use context propagation together with manually created spans. I removed the memory leak - now it should be better.