A Sample JAX-RS resource intended to illustrate usage of the Metrics API.

MetricsSample.java

package com.hdd;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;
import com.yammer.metrics.Metrics;
import com.yammer.metrics.annotation.ExceptionMetered;
import com.yammer.metrics.annotation.Gauge;
import com.yammer.metrics.annotation.Metered;
import com.yammer.metrics.annotation.Timed;
import com.yammer.metrics.core.Counter;
import com.yammer.metrics.core.Histogram;
import com.yammer.metrics.reporting.ConsoleReporter;

import javax.ws.rs.*;
import javax.ws.rs.core.Response;
import java.util.List;
import java.util.Random;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

@Path("/sample")
public class SampleResource {

    // Uniform Histogram    
    private static final Histogram resultSizes
            = Metrics.newHistogram(SampleResource.class, "resultSizes", false);

    private static final Counter activeSessions
            = Metrics.newCounter(SampleResource.class, "activeSessions");

    static {
        ConsoleReporter.enable(5, TimeUnit.MINUTES);
    }

    private final Iterable<Integer> searchResults = Iterables.cycle(1, 2, 3, 4, 5);
    private final AtomicLong sessionIdSequence = new AtomicLong(0);
    private final Random random = new Random();

    @GET
    @ExceptionMetered
    @Path("/search-results")
    public List<Integer> getSearchResults() {
        List<Integer> results
                = ImmutableList.copyOf(
                        Iterables.limit(searchResults, random.nextInt(25)));
        resultSizes.update(results.size());
        return results;
    }

    @GET
    @Metered
    @ExceptionMetered
    @Path("/high-volume-resource")
    public String getHighVolumeResource() {
        try {
            // Do some stuff, maybe throw an exception, but mostly:
            Thread.sleep(random.nextLong(1000));
            return "OH HI!";
        } catch (Exception e) {
            throw new WebApplicationException(e,
                    Response.serverError().entity("Oh NOES!").build());
        }
    }

    @GET
    @Timed
    @ExceptionMetered
    @Path("/high-latency-resource")
    public String getHighLatencyResource() {
        try {
            // Do some stuff, maybe throw an exception, but mostly:
            Thread.sleep(random.nextLong(1000));
            return "OH HI!";
        } catch (Exception e) {
            throw new WebApplicationException(e,
                    Response.serverError().entity("Oh NOES!").build());
        }
    }

    @POST
    @ExceptionMetered
    @Path("/session")
    public long startSession() {
        long id = sessionIdSequence.incrementAndGet();
        activeSessions.inc();
        return id;
    }

    @DELETE
    @ExceptionMetered
    @Path("/session/{id}")
    public String endSession(@PathParam("id") long id) {
        // delete session here
        activeSessions.dec();
        return "Deleted!";
    }

    @Gauge
    public long highestSessionId() {
        return sessionIdSequence.get();
    }
}