Also allows us to actually create a PercentageBasedSampler (I
don't think anyone tried it before) without resorting to
lazy beans and proxies.
Another freature added here is a default percentage sampler
if we know that spans need to be exported (zipkin or stream
is present).
Fixes gh-138
Changes following review
- Reusing CounterService to automatically profit from Dropwizard if present
- NoOp is the default impl for SpanReporterService
- SpanReporterService has configurable metric names (it's enough to change the
name to 'meter.a.b.c' to profit from Dropwizard's meters)
Fixes gh-99
It still feels brittle because it's up to the suthor of the
instrumentation. This patches all the places where we were still
using Long instead of Long.toHexString(..).
Fixes gh-125
Previously, sleuth logged more data than necessary. This led to issues
including spans approaching megabytes each. This pares down default keys
to a minimal set, but allows users to opt-into logging more by extending
`TraceFilter`.
- Changed Random instantiation to a shared Random
- Changed the name of the converter
- Changed generator into random
- Span id is now non-nullable.
- it gets generated in the http filter if it's not there
- it's generated in the spring-integration channels if it wasn't set
Brave's span collector, which turned out to not be a great tool for
direct use. Brave internally creates spans before sending to its
collector, so validation is implicit. The flip side of this is using the
collector directly does not validate spans. This means it is easy to
send invalid ones, for example missing span names. The problem is more
difficult as the data is in binary (thrift).
This introduces HttpZipkinSpanReporter, which validates via zipkin-java
classes before sending on the wire. Moreover, this sends in json to make
debugging problems easier.
This does not fully remove the Brave dependency, as further work is
needed. Particularly, Brave is indirectly referenced in other code.
See https://github.com/openzipkin/zipkin-java/issues/68
See #98 (Reporter is an OpenTracing term)
It's not really necessary to use rabbit, but the existing tests
weren't really using the stream components at all because
zipkin spans were being collected by spring-cloud-sleuth-zipkin.
Zipkin 0.4.1 obviates some duplication of configuration. It is also the
first version that's published as a docker image.
By switching to the published image of zipkin-java, we can be more
consistent, as `spring-cloud-sleuth-zipkin-stream` is derived from that,
not the scala query service.
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.
