Problem

When using a thread pool, TraceSegment data in a thread cannot be reported and there are memory data that cannot be recycled (memory leaks).

Example

    ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
    executor.setThreadFactory(r -> new Thread(RunnableWrapper.of(r)));

Reason

• Worker threads are enhanced when using the thread pool.
• Based on the design of the SkyWalking Java Agent, when tracing a cross thread, you must enhance the task thread.

Resolution

• When using Thread Schedule Framework: See SkyWalking Thread Schedule Framework at SkyWalking Java agent supported list, such as Spring FrameWork @Async, which can implement tracing without any modification.

• When using Custom Thread Pool: Enhance the task thread with the following code.

    ExecutorService executorService = Executors.newFixedThreadPool(1);
    executorService.execute(RunnableWrapper.of(new Runnable() {
        @Override public void run() {
            //your code
        }
    }));

See across thread solution APIs for more use cases.