This moves to changes made in preparation of zipkin 1.0.
Here are the notables:
* Zipkin has autoconfiguration modules, where maven artifacts have the prefix 'zipkin-autoconfigure-X'
* Zipkin's ui now shares a version with everything else
* Zipkin now namespaces packages and configuration. ex zipkin.storage.X as opposed to zipkin.X
* All autoconfiguration classes are prefixed `Zipkin` to be easier to find
* Zipkin binds components like StorageComponent, as opposed to individual classes like SpanStore.
* Health checks are under the scope "zipkin" and broken down by component
* UI responsiveness is better by conditionally caching names queries for 5 minutes
* New `Collector` class, which makes logging and metrics patterns the same regardless of transport
Removes wiremock as a test dependency in core (which created more
issues than you might expect because Tomcat and Jetty don't treay
HTTP headers in the same way apparently).
Also moves the spring-messaging dependency to where it is needed
in sleuth stream.
Recent versions of zipkin and brave operate with http instead of scribe.
This changes the implementation accordingly, as well adds a sampler to
the POST endpoint.
A notable impact is that we no longer require a collector process, as
the zipkin server's POST endpoint is a collector.
Missing service name:
Zipkin service names were logged as null, which is invalid and led to
them showing up as "unknown" in the zipkin ui. This was due to a wiring
bug, and a special-case, which this change fixes.
The special-case was when a sleuth span had no annotations. Since zipkin
service names are attached to annotations, they are only queryable when
annotations exist. When there are no annotations, we add the "lc"
binary annotation, which makes that span attached to the correct service
in zipkin.
Polishing:
Zipkin timestamps were not always set as microseconds. This fixes that.
The de-facto label in zipkin for unknown service is "unknown". This
fixes the code, which formerly fell back to "application".
This also removes complexity in assigning timestamp and duration as we
no longer need to make pseudo-annotations "acquire" and "release".
Finally, this adds tests about above consistently to both scs-zipkin and
scs-zipkin-stream.
Still not quite working:
$ docker-compose -f docker-compose.yml -f docker-compose.zipkin.yml up
everything starts up fine (once the database is initialized), but
the zipkin server is not listening to rabbit (and there are errors
in the logs).
@EnableZipkinStreamServer and bind to a Spring Cloud Stream message
broker. That's it. The default span store is in memory, but Zipkin
also supports MySQL (and Cassandra coming soon).
