org.apache.hadoop.ha.TestHealthMonitor.java Source code

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Here is the source code for org.apache.hadoop.ha.TestHealthMonitor.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.hadoop.ha;

import static org.junit.Assert.*;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.util.concurrent.atomic.AtomicInteger;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeys;
import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
import org.apache.hadoop.ha.HealthMonitor.Callback;
import org.apache.hadoop.ha.HealthMonitor.State;
import org.apache.hadoop.util.Time;

import org.junit.Before;
import org.junit.Test;

public class TestHealthMonitor {
    private static final Log LOG = LogFactory.getLog(TestHealthMonitor.class);

    /** How many times has createProxy been called */
    private AtomicInteger createProxyCount = new AtomicInteger(0);
    private volatile boolean throwOOMEOnCreate = false;

    private HealthMonitor hm;

    private DummyHAService svc;

    @Before
    public void setupHM() throws InterruptedException, IOException {
        Configuration conf = new Configuration();
        conf.setInt(CommonConfigurationKeys.IPC_CLIENT_CONNECT_MAX_RETRIES_KEY, 1);
        conf.setInt(CommonConfigurationKeys.HA_HM_CHECK_INTERVAL_KEY, 50);
        conf.setInt(CommonConfigurationKeys.HA_HM_CONNECT_RETRY_INTERVAL_KEY, 50);
        conf.setInt(CommonConfigurationKeys.HA_HM_SLEEP_AFTER_DISCONNECT_KEY, 50);

        svc = createDummyHAService();
        hm = new HealthMonitor(conf, svc) {
            @Override
            protected HAServiceProtocol createProxy() throws IOException {
                createProxyCount.incrementAndGet();
                if (throwOOMEOnCreate) {
                    throw new OutOfMemoryError("oome");
                }
                return super.createProxy();
            }
        };
        LOG.info("Starting health monitor");
        hm.start();

        LOG.info("Waiting for HEALTHY signal");
        waitForState(hm, HealthMonitor.State.SERVICE_HEALTHY);
    }

    protected DummyHAService createDummyHAService() {
        return new DummyHAService(HAServiceState.ACTIVE, new InetSocketAddress("0.0.0.0", 0), true);
    }

    @Test(timeout = 15000)
    public void testMonitor() throws Exception {
        LOG.info("Mocking bad health check, waiting for UNHEALTHY");
        svc.isHealthy = false;
        waitForState(hm, HealthMonitor.State.SERVICE_UNHEALTHY);

        LOG.info("Returning to healthy state, waiting for HEALTHY");
        svc.isHealthy = true;
        waitForState(hm, HealthMonitor.State.SERVICE_HEALTHY);

        LOG.info("Returning an IOException, as if node went down");
        // should expect many rapid retries
        int countBefore = createProxyCount.get();
        svc.actUnreachable = true;
        waitForState(hm, HealthMonitor.State.SERVICE_NOT_RESPONDING);

        // Should retry several times
        while (createProxyCount.get() < countBefore + 3) {
            Thread.sleep(10);
        }

        LOG.info("Returning to healthy state, waiting for HEALTHY");
        svc.actUnreachable = false;
        waitForState(hm, HealthMonitor.State.SERVICE_HEALTHY);

        hm.shutdown();
        hm.join();
        assertFalse(hm.isAlive());
    }

    /**
     * Test that the proper state is propagated when the health monitor
     * sees an uncaught exception in its thread.
     */
    @Test(timeout = 15000)
    public void testHealthMonitorDies() throws Exception {
        LOG.info("Mocking RTE in health monitor, waiting for FAILED");
        throwOOMEOnCreate = true;
        svc.actUnreachable = true;
        waitForState(hm, HealthMonitor.State.HEALTH_MONITOR_FAILED);
        hm.shutdown();
        hm.join();
        assertFalse(hm.isAlive());
    }

    /**
     * Test that, if the callback throws an RTE, this will terminate the
     * health monitor and thus change its state to FAILED
     * @throws Exception
     */
    @Test(timeout = 15000)
    public void testCallbackThrowsRTE() throws Exception {
        hm.addCallback(new Callback() {
            @Override
            public void enteredState(State newState) {
                throw new RuntimeException("Injected RTE");
            }
        });
        LOG.info("Mocking bad health check, waiting for UNHEALTHY");
        svc.isHealthy = false;
        waitForState(hm, HealthMonitor.State.HEALTH_MONITOR_FAILED);
    }

    private void waitForState(HealthMonitor hm, State state) throws InterruptedException {
        long st = Time.now();
        while (Time.now() - st < 2000) {
            if (hm.getHealthState() == state) {
                return;
            }
            Thread.sleep(50);
        }
        assertEquals(state, hm.getHealthState());
    }
}