metrics-feign

A decorator wrapping Feign client method handlers in order to provide Dropwizard Metrics of calls to feign target interfaces.

Usage

Basically you only have to replace Feign.builder() with FeignWithMetrics.builder(metricRegistry).

  @Timed
  @Metered
  @ExceptionMetered
  @ResponseMetered
  interface GitHub {
    @RequestLine("GET /repos/{owner}/{repo}/contributors")
    List<Contributor> contributors(@Param("owner") String owner, @Param("repo") String repo);
  }

  static class Contributor {
    String login;
    int contributions;
  }

  public static void main(final String... args) {

    final MetricRegistry metricRegistry = new MetricRegistry();

    final ConsoleReporter reporter =
        ConsoleReporter.forRegistry(metricRegistry).convertRatesTo(TimeUnit.SECONDS)
            .convertDurationsTo(TimeUnit.MILLISECONDS).build();

    final GitHub github =
        FeignWithMetrics.builder(metricRegistry).decoder(new GsonDecoder())
            .target(GitHub.class, "https://api.github.com");
    try {
      // Fetch and print a list of the contributors to this library.
      final List<Contributor> contributors = github.contributors("mwiede", "metrics-feign");
      for (final Contributor contributor : contributors) {
        System.out.println(contributor.login + " (" + contributor.contributions + ")");
      }
    } finally {
      reporter.report();
    }
  }

List of provided metrics

Based of the example above, the following metrics were registered and reported:

Meters

com.github.mwiede.metrics.example.Example$GitHub.contributors.1xx-responses
com.github.mwiede.metrics.example.Example$GitHub.contributors.2xx-responses
com.github.mwiede.metrics.example.Example$GitHub.contributors.3xx-responses
com.github.mwiede.metrics.example.Example$GitHub.contributors.4xx-responses
com.github.mwiede.metrics.example.Example$GitHub.contributors.5xx-responses
com.github.mwiede.metrics.example.Example$GitHub.contributors.Metered
com.github.mwiede.metrics.example.Example$GitHub.contributors.exceptions
com.github.mwiede.metrics.example.Example$GitHub.contributors.reAttempts.Metered
com.github.mwiede.metrics.example.Example$GitHub.contributors.retryExhausted.Metered

Timers

com.github.mwiede.metrics.example.Example$GitHub.contributors.Timed

Download

You can use this library via maven: