NOTE
This README is currently incomplete / unfinished. Please refer to respective README in tutorials for one of the other languages
Learn how to:
- Trace a transaction across more than one microservice
- Pass the context between processes using
InjectandExtract - Apply OpenTracing-recommended tags
To test it out, first run the formatter and publisher services in separate terminals
# terminal 1
$ node lesson03/solution/formatter.js
* Running on http://localhost:8081/ (Press CTRL+C to quit)
# terminal 3
$ node lesson03/solution/publisher.js
* Running on http://localhost:8082/ (Press CTRL+C to quit)
Finally, if we run the client app as we did in the previous lessons:
$ node lesson03/solution/hello.js Peter
INFO Initializing Jaeger Tracer with CompositeReporter and ConstSampler
Hello app listening on port 8080
INFO Reporting span 80c31f112061d86e:1def63dfd6d6755d:80c31f112061d86e:1
INFO Reporting span 80c31f112061d86e:e47ca83f948cb0c4:80c31f112061d86e:1
INFO Reporting span 80c31f112061d86e:80c31f112061d86e:0:1
On formatter terminal screen:
INFO Initializing Jaeger Tracer with CompositeReporter and ConstSampler
Formatter app listening on port 8081
INFO Reporting span 80c31f112061d86e:9ad7c16acf5f0994:1def63dfd6d6755d:1
On publisher terminal screen:
INFO Initializing Jaeger Tracer with CompositeReporter and ConstSampler
Publisher app listening on port 8082
Hello, Peter!
INFO Reporting span 80c31f112061d86e:f3211e5bb77c5f2b:e47ca83f948cb0c4:1
Since we turned our single-binary program into a distributed application that makes remote calls, we need to handle errors that may occur during communications. It is a good practice to tag the span with the tag error=true if the operation represented by the span failed. We have handled errors in the error section of the http_get function.
If either of the Publisher or Formatter are down, our client app will report the error to Jaeger. Jaeger will highlight all such errors in the UI corresponding to the failed span.