hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/io/retry/TestDefaultRetryPolicy.java

/**
 * 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
 * <p/>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p/>
 * 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.io.retry;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.ipc.RemoteException;
import org.apache.hadoop.ipc.RetriableException;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.Timeout;

import java.io.IOException;

import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertThat;

/**
 * Test the behavior of the default retry policy.
 */
public class TestDefaultRetryPolicy {
  @Rule
  public Timeout timeout = new Timeout(30000);

  /** Verify FAIL < RETRY < FAILOVER_AND_RETRY. */
  @Test
  public void testRetryDecisionOrdering() throws Exception {
    Assert.assertTrue(RetryPolicy.RetryAction.RetryDecision.FAIL.compareTo(
        RetryPolicy.RetryAction.RetryDecision.RETRY) < 0);
    Assert.assertTrue(RetryPolicy.RetryAction.RetryDecision.RETRY.compareTo(
        RetryPolicy.RetryAction.RetryDecision.FAILOVER_AND_RETRY) < 0);
    Assert.assertTrue(RetryPolicy.RetryAction.RetryDecision.FAIL.compareTo(
        RetryPolicy.RetryAction.RetryDecision.FAILOVER_AND_RETRY) < 0);
  }

  /**
   * Verify that the default retry policy correctly retries
   * RetriableException when defaultRetryPolicyEnabled is enabled.
   *
   * @throws IOException
   */
  @Test
  public void testWithRetriable() throws Exception {
    Configuration conf = new Configuration();
    RetryPolicy policy = RetryUtils.getDefaultRetryPolicy(
        conf, "Test.No.Such.Key",
        true,                     // defaultRetryPolicyEnabled = true
        "Test.No.Such.Key", "10000,6",
        null);
    RetryPolicy.RetryAction action = policy.shouldRetry(
        new RetriableException("Dummy exception"), 0, 0, true);
    assertThat(action.action,
        is(RetryPolicy.RetryAction.RetryDecision.RETRY));
  }

  /**
   * Verify that the default retry policy correctly retries
   * a RetriableException wrapped in a RemoteException when
   * defaultRetryPolicyEnabled is enabled.
   *
   * @throws IOException
   */
  @Test
  public void testWithWrappedRetriable() throws Exception {
    Configuration conf = new Configuration();
    RetryPolicy policy = RetryUtils.getDefaultRetryPolicy(
        conf, "Test.No.Such.Key",
        true,                     // defaultRetryPolicyEnabled = true
        "Test.No.Such.Key", "10000,6",
        null);
    RetryPolicy.RetryAction action = policy.shouldRetry(
        new RemoteException(RetriableException.class.getName(),
            "Dummy exception"), 0, 0, true);
    assertThat(action.action,
        is(RetryPolicy.RetryAction.RetryDecision.RETRY));
  }

  /**
   * Verify that the default retry policy does *not* retry
   * RetriableException when defaultRetryPolicyEnabled is disabled.
   *
   * @throws IOException
   */
  @Test
  public void testWithRetriableAndRetryDisabled() throws Exception {
    Configuration conf = new Configuration();
    RetryPolicy policy = RetryUtils.getDefaultRetryPolicy(
        conf, "Test.No.Such.Key",
        false,                     // defaultRetryPolicyEnabled = false
        "Test.No.Such.Key", "10000,6",
        null);
    RetryPolicy.RetryAction action = policy.shouldRetry(
        new RetriableException("Dummy exception"), 0, 0, true);
    assertThat(action.action,
        is(RetryPolicy.RetryAction.RetryDecision.FAIL));
  }
}