zipkin-finagle

Integration between Finagle tracing to Zipkin transports including http, kafka and scribe.

Quick start

Finagle will use a tracer that it detects in the classpath. For example, depending on io.zipkin.finagle2:zipkin-finagle-http_2.12 will send to Zipkin over Http.

You can look at the example for this in use.

Choosing a tracer explicitly

You can also explicitly choose a tracer, which is more reliable, at the tradeoff of more configuration.

Here an example initializing an http client in scala and java

client = Http.client
             .withTracer(new HttpZipkinTracer())
             .withLabel("frontend") // becomes the zipkin service name
             .newService("remotehost:8080");

client = Http$.MODULE$.client()
              .withTracer(new HttpZipkinTracer())
              .withLabel("frontend") // becomes the zipkin service name
              .newService("remotehost:8080");

Note on service names

Sometimes labels used in Finagle do not match the intent of the Zipkin service name. If your traces or dependency graph looks incorrect, set the flag zipkin.localServiceName. This will ignore any of the labels set by servers. In clients, the ServiceName recorded by Finagle will be moved to span.remoteEndpoint.serviceName in Zipkin under the assumption that it was intended to name the remote host.

Configuration

Global Flags

zipkin-finagle configuration is via global flags.

Global flags can either be set by system property, or commandline argument (ex if using TwitterServer).

Ex the following are equivalent ways to trace every request:

$ java -Dzipkin.localServiceName=favstar  -Dzipkin.initialSampleRate=1.0 ...
$ java -cp my-twitter-server.jar -zipkin.localServiceName=favstar -zipkin.initialSampleRate=1.0

Here are the flags that apply to all transports:

Http Configuration

Adding io.zipkin.finagle2:zipkin-finagle-http_2.12 to your classpath will configure Finagle to report trace data to a Zipkin server via HTTP.

Here are the flags that apply to Http:

Ex. Here's how to configure the Zipkin server with a system property:

$ java -Dzipkin.http.host=192.168.99.100:9411 ...

Kafka Configuration

Adding io.zipkin.finagle2:zipkin-finagle-kafka_2.12 to your classpath will configure Finagle to report trace data to a Kafka topic. The minimum Kafka server version is 0.10

Here are the flags that apply to Kafka:

Ex. Here's how to configure the Kafka server with a system property:

$ java -Dzipkin.kafka.bootstrapServers=192.168.99.100 ...

Scribe Configuration

Adding io.zipkin.finagle2:zipkin-finagle-scribe_2.12 to your classpath will configure Finagle to report trace data to the zipkin category of Scribe.

Here are the flags that apply to Scribe:

Ex. Here's how to configure the Scribe host with a system property. In this case pointing directly to a zipkin server:

$ java -Dzipkin.scribe.host=zipkinhost:9410 ...

Programmatic

You can also configure zipkin tracers programmatically. Here's an example:

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()));

Custom

You may need to use alternative reporters like zipkin-aws, control configuration not available in flags, or change metrics reporting configuration. To do that, use ZipkinReporter.newBuilder() and supply the arguments you need.

// Setup a sender without using Finagle flags like so:
Properties overrides = new Properties();
overrides.put(ProducerConfig.MAX_BLOCK_MS_CONFIG, 5000);
sender = KafkaSender.newBuilder()
  .bootstrapServers("host1:9092,host2:9092")
  .overrides(overrides)
  .encoding(Encoding.PROTO3)
  .build();

zipkinStats = stats.scope("zipkin");
spanReporter = AsyncReporter.builder(sender)
  .metrics(new ReporterMetricsAdapter(zipkinStats)) // routes reporter metrics to finagle stats
  .build()

// Now, use it here, but don't forget to close the sender!
tracer = ZipkinTracer.newBuilder(spanReporter).stats(zipkinStats).build();

Metrics

The following metrics are reported under a transport-specific category to the configured StatsReceiver. For example, if using kafka, they are reported relative to "zipkin.kafka".

Artifacts

All artifacts publish to the group ID "io.zipkin.finagle2". We use a common release version for all components.

Library Releases

Releases are at Sonatype and Maven Central

Library Snapshots

Snapshots are uploaded to Sonatype after commits to master.