[HDFS-11622] TraceId hardcoded to 0 in DataStreamer, correlation between multiple spans is lost

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: tracing
• Assignee: Unassigned
• Reporter: Karan Mehta
• Created: 04/Apr/17 22:22
• Updated: 13/Apr/17 09:50

Description

In the run() method of DataStreamer class, the following code is written. parents[0] refer to the spanId of the parent span.

              one = dataQueue.getFirst(); // regular data packet
              long parents[] = one.getTraceParents();
              if (parents.length > 0) {
                     scope = Trace.startSpan("dataStreamer", new TraceInfo(0, parents[0]));
                // TODO: use setParents API once it's available from HTrace 3.2
                // scope = Trace.startSpan("dataStreamer", Sampler.ALWAYS);
                // scope.getSpan().setParents(parents);
              }

The scope starts a new TraceSpan with a traceId hardcoded to 0. Ideally it should be taken when currentPacket.addTraceParent(Trace.currentSpan()) is invoked. This JIRA is to propose an additional long field inside the DFSPacket class which holds the parent traceId.