Cat异步Transaction丢失Context

[flyingglass]

Describe the bug Cat Transaction在多个线程之间切换会丢失调用链

Expected behavior Cat Transaction可以再多个线程间传递，比如SpringCloud Gateway。 看Cat Client的源码DefaultMessageManager有变量ThreadLocal context，目前解思路在配合Java Agent的情况在比如对特定的场景（Runnable, Callable , @Async, Thread, ThreadPool, Webflux等）进行增强，完成context的传递，就能实现Transaction在上述异步场景传递的问题。

因为对Cat Client深入有限，按照上述思路除了DefaultMessageManager的context变量，是否还需要涉及到其他地方context传递问题？

[zhisrc]

可以尝试 forkableTransaction public class Test {

static class TestTask implements Runnable {

    ForkableTransaction m_forkable;
    int m_index;

    TestTask(ForkableTransaction t, int i) {
        m_forkable = t;
        m_index = i;
    }

    @Override
    public void run() {
        try (ForkedTransaction ignored = m_forkable.doFork()) {
            Transaction t = Cat.newTransaction("foo-" + String.valueOf(m_index), "bar");
            Thread.sleep(50);
            t.complete();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }
}

public static void main(String[] args) {
    Cat.initializeByDomain("bcat");

    Transaction t = Cat.newTransaction("foo", "bar");
    try {
        ForkableTransaction ft = t.forFork();
        Thread.sleep(30);
        new Thread(new TestTask(ft, 1)).start();
        Thread.sleep(30);
        new Thread(new TestTask(ft, 2)).start();
        Thread.sleep(30);
        new Thread(new TestTask(ft, 3)).start();
        Thread.sleep(30);
    } catch (InterruptedException e) {
        e.printStackTrace();
    } finally {
        t.complete();
    }

    try {
        Thread.sleep(1000);
    } catch (InterruptedException e) {
        e.printStackTrace();
    }
}

}

[zhisrc]

[flyingglass]

可能使用场景略微不同，主要用于reactor框架，可能上述方式比较复杂和笨重，已采用skywalking进行处理