HystrixThreadPoolMetricsTest.java

/**
 * Copyright 2015 Netflix, Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.netflix.hystrix;

import com.netflix.hystrix.metric.consumer.RollingThreadPoolEventCounterStream;
import org.junit.Before;
import org.junit.Test;

import java.util.Collection;

import static org.junit.Assert.assertEquals;

public class HystrixThreadPoolMetricsTest {

    private static final HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey("HystrixThreadPoolMetrics-UnitTest");
    private static final HystrixThreadPoolKey tpKey = HystrixThreadPoolKey.Factory.asKey("HystrixThreadPoolMetrics-ThreadPool");

    @Before
    public void resetAll() {
        HystrixThreadPoolMetrics.reset();
    }

    @Test
    public void shouldYieldNoExecutedTasksOnStartup() throws Exception {
        //given
        final Collection<HystrixThreadPoolMetrics> instances = HystrixThreadPoolMetrics.getInstances();

        //then
        assertEquals(0, instances.size());

    }
    @Test
    public void shouldReturnOneExecutedTask() throws Exception {
        //given
        RollingThreadPoolEventCounterStream.getInstance(tpKey, 10, 100).startCachingStreamValuesIfUnstarted();

        new NoOpHystrixCommand().execute();
        Thread.sleep(100);

        final Collection<HystrixThreadPoolMetrics> instances = HystrixThreadPoolMetrics.getInstances();

        //then
        assertEquals(1, instances.size());
        HystrixThreadPoolMetrics metrics = instances.iterator().next();
        assertEquals(1, instances.iterator().next().getRollingCountThreadsExecuted());
    }

    private static class NoOpHystrixCommand extends HystrixCommand<Void> {
        public NoOpHystrixCommand() {
            super(Setter.withGroupKey(groupKey)
                    .andThreadPoolKey(tpKey)
                    .andThreadPoolPropertiesDefaults(HystrixThreadPoolProperties.Setter().withMetricsRollingStatisticalWindowInMilliseconds(100)));
        }

        @Override
        protected Void run() throws Exception {
            System.out.println("Run in thread : " + Thread.currentThread().getName());
            return null;
        }
    }
}