How to log the parentSpanId? about brave-example

[codefromthecrypt]

why do you need parentSpanId? It isn't supported out of the box.

[sstong123]

For log data analysis,also need to know the call chains.

[codefromthecrypt]

please file an issue in brave. If others want this too, we can change the code to add this to the context. In the mean time, you can copy/paste the code and add the parentId yourself.

…

On Tue, Nov 21, 2017 at 2:09 PM, sstong123 ***@***.***> wrote: For log data analysis,also need to know the call chains. — You are receiving this because you commented. Reply to this email directly, view it on GitHub <#18 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAD616tkAL8xkmWDf47cV4cgM3RmCTz0ks5s4ncegaJpZM4QZHLi> .

[sstong123]

1). I customized the brave example code to add the parentSpanId as below:

import brave.internal.HexCodec;
import brave.internal.Nullable;
import brave.propagation.CurrentTraceContext;
import brave.propagation.TraceContext;
import org.apache.logging.log4j.ThreadContext;

/**
 * Adds {@linkplain ThreadContext} properties "traceId" , "spanId" and "parentSpanId" when a {@link
 * brave.Tracer#currentSpan() span is current}. These can be used in log correlation.
 */
public final class MyThreadContextCurrentTraceContext extends CurrentTraceContext {
  public static MyThreadContextCurrentTraceContext create() {
    return create(CurrentTraceContext.Default.inheritable());
  }

  public static MyThreadContextCurrentTraceContext create(CurrentTraceContext delegate) {
    return new MyThreadContextCurrentTraceContext(delegate);
  }

  final CurrentTraceContext delegate;

  MyThreadContextCurrentTraceContext(CurrentTraceContext delegate) {
    if (delegate == null) throw new NullPointerException("delegate == null");
    this.delegate = delegate;
  }

  @Override public TraceContext get() {
    return delegate.get();
  }

  @Override public Scope newScope(@Nullable TraceContext currentSpan) {
    final String previousTraceId = ThreadContext.get("traceId");
    final String previousSpanId = ThreadContext.get("spanId");

    if (currentSpan != null) {
      ThreadContext.put("traceId", currentSpan.traceIdString());
      ThreadContext.put("spanId", HexCodec.toLowerHex(currentSpan.spanId()));
      Long parentId= currentSpan.parentId();     
      if(parentId!=null){
    	  String pid=HexCodec.toLowerHex(parentId);
    	  ThreadContext.put("parentSpanId",pid);
      }
      
    } else {
      ThreadContext.remove("traceId");
      ThreadContext.remove("spanId");
      ThreadContext.remove("parentSpanId");
    }

    final Scope scope = delegate.newScope(currentSpan);
    class ThreadContextCurrentTraceContextScope implements Scope {
      @Override public void close() {
        scope.close();
        ThreadContext.put("traceId", previousTraceId);
        ThreadContext.put("spanId", previousSpanId);
      }
    }
    return new ThreadContextCurrentTraceContextScope();
  }
}

2). add the below line in log4j config file:
[%X{traceId}/%X{spanId}/%X{parentSpanId}]

3). after I sent the request to the parent system,I got parentSpanId:""(blank) that is correct,
but after resent the request to parent system for several times(about 10 times), I got the parentSpanId not blank,why this happened?(it should be blank)

[sstong123]

filed in brave