Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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2.21.1
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None
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Unknown
Description
Camel-Zipkin does not report traces with root span id when there are multiple routes.
For example:
from("direct:foo") .delay(1000) .to("direct:bar") .to("direct:moo") .to("direct:tar"); from("direct:bar") .delay(2000); from("direct:moo") .delay(1000); from("direct:tar") .delay(3000);
Root SpanId(TraceId) should be for service-name = direct:foo and the trace in UI should show all the 4 routes in one sequence. But it breaks. Check the attached screenshot: Traces Breaking.png
I looked into the code and figured out why its happening. Here is the code which is breaking the functionality.
Class Name: ZipkinTracer.ZipkinRoutePolicy
Inside onExchangeBegin() method
// add on completion after the route is done, but before the consumer writes the response // this allows us to track the zipkin event before returning the response which is the right time exchange.addOnCompletion(new SynchronizationAdapter() { @Override public void onAfterRoute(Route route, Exchange exchange) { String serviceName = getServiceName(exchange, route.getEndpoint(), true, false); Brave brave = getBrave(serviceName); if (brave != null) { serverResponse(brave, serviceName, exchange); } } @Override public String toString() { return "ZipkinTracerOnCompletion[" + routeId + "]"; } });
Using onAfterRoute() : if the exchange is being routed through multiple routes, there will be callbacks for each route.
I have fix for it:
If I use onExchangeDone() instead of above code. The traces are reported properly. Check screenshots.
https://zipkin.io/pages/instrumenting.html
Note This process must be repeated if the service makes multiple downstream calls. That is each subsequent span will have the same trace id and parent id, but a new and different span id.
