Bumps to finagle 18.2.0

Merge pull request #40 from chris-vale-ck/feature/18.2.0

another month, another version of finagle

Zipkin Finagle Tracer 1.1

The Zipkin Finagle Tracer 1.1 is the same as v1.0.1, except is compiled against Finagle 7.1.

Zipkin Finagle Tracer 0.4

Starting in version 0.4 zipkin-finagle is built and published against scala 2.12. If you need changes backported to 0.3.x please raise an issue as you encounter them.

Thanks to @crispywalrus for the help making this happen.

Zipkin Finagle Tracer 0.3.6

Zipkin Finagle Tracer 0.3.6 fixes flags, so that you can specify them via commandline args, not just system properties. Thanks to @melgenek for reporting this and how to fix it.

Zipkin Finagle Tracer 0.3

The latest version of the Zipkin Finagle tracer supports all three transports: http, kafka and scribe

If you want a playground, use the example project.

Under the hood, it uses the new Zipkin reporter library to defer sending spans out of process. This means that when tracing is enabled, transient problems connecting to Kafka or otherwise will not impact your apps.

This version defines a complete set of metrics, which you can use to understand your tracing throughput in terms of bytes or spans.

Metric	Description
spans	the count of spans recorded by the tracer
span_bytes	the count of encoded span bytes recorded by the tracer
spans_dropped	the count of spans dropped for any reason. For example, failure queueing or sending.
messages	the count of messages sent to zipkin. Ex POST requests or Kafka messages.
message_bytes	the count of encoded message bytes sent. This includes encoding overhead and excludes compression.
messages_dropped/exception_class_name+	count of messages dropped broken down by cause.
span_queue_size	last count of spans in the pending queue
span_queue_bytes	last count of encoded span bytes in the pending queue

While this is pre-1.0, we'd appreciate your taking it for a spin so that we can make a 1.0! If you have any feedback, please report on issues or gitter.

Zipkin Finagle Tracer 0.2

Zipkin Finagle Tracer 0.2 has been rewritten in java to make it easier to maintain and implement current zipkin practice. Here are some highlights.

• When reporting, span.timestamp and span.duration fields are now set
• zipkin-finagle-http now posts compressed json instead of thrift. (compression can be disabled for testing)
• Numerous behavior tests have been backfiled, many of which were never present upstream.
• Programmatic configuration is now possible.

Here's an example of explicitly configuring an HTTP tracer as opposed to using flags. This approach is used in the example codebase.

HttpZipkinTracer.Config config = HttpZipkinTracer.Config.builder()
    // The frontend makes a sampling decision (via Trace.letTracerAndId) and propagates it downstream.
    // This property says sample 100% of traces.
    .initialSampleRate(1.0f)
    // All servers need to point to the same zipkin transport
    .host("127.0.0.1:9411").build();

Tracer tracer = HttpZipkinTracer.create(config,
    // print stats about zipkin to the console
    new JavaLoggerStatsReceiver(Logger.getAnonymousLogger()));

Unrelated to the rewrite, we now support com.twitter.finagle.Name as a builder arg or flag value for "zipkin.http.host". This allows you to specify a list of addresses or a symbolic name.