[
https://issues.apache.org/jira/browse/HDFS-11622?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15960078#comment-15960078
]
Masatake Iwasaki commented on HDFS-11622:
-----------------------------------------
bq. The DFSPacket initializes the parents field when it is dumping the data in
dataQueue with the line packet.addTraceParent(Tracer.getCurrentSpanId()), thus
getting current trace from the ThreadLocal. At this point, I feel that we can
also get the value of trace ID and add the info inside the DFSPacket. Any
thoughts on this one?
As you pointed out, the current {{dataStreamer}} span in branch-2.7 seems not
to have situation setting multiple parents. It looks like extention for future
use?
> TraceId hardcoded to 0 in DataStreamer, correlation between multiple spans is
> lost
> ----------------------------------------------------------------------------------
>
> Key: HDFS-11622
> URL: https://issues.apache.org/jira/browse/HDFS-11622
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: tracing
> Reporter: Karan Mehta
>
> In the {{run()}} method of {{DataStreamer}} class, the following code is
> written. {{parents\[0\]}} refer to the {{spanId}} of the parent span.
> {code}
> 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);
> }
> {code}
> 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}}.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
