hadoop RetryUtils 源码

  • 2022-10-20
  • 浏览 (452)

haddop RetryUtils 代码

文件路径:/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/io/retry/RetryUtils.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
 *
 *     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.io.retry;

import java.io.IOException;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.retry.RetryPolicies.MultipleLinearRandomRetry;
import org.apache.hadoop.ipc.RemoteException;

import org.apache.hadoop.thirdparty.protobuf.ServiceException;
import org.apache.hadoop.ipc.RetriableException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class RetryUtils {
  public static final Logger LOG = LoggerFactory.getLogger(RetryUtils.class);
  
  /**
   * Return the default retry policy set in conf.
   * 
   * If the value retryPolicyEnabledKey is set to false in conf,
   * use TRY_ONCE_THEN_FAIL.
   * 
   * Otherwise, get the MultipleLinearRandomRetry policy specified in the conf
   * and then
   * (1) use multipleLinearRandomRetry for
   *     - remoteExceptionToRetry, or
   *     - IOException other than RemoteException, or
   *     - ServiceException; and
   * (2) use TRY_ONCE_THEN_FAIL for
   *     - non-remoteExceptionToRetry RemoteException, or
   *     - non-IOException.
   *     
   *
   * @param conf configuration.
   * @param retryPolicyEnabledKey     conf property key for enabling retry
   * @param defaultRetryPolicyEnabled default retryPolicyEnabledKey conf value 
   * @param retryPolicySpecKey        conf property key for retry policy spec
   * @param defaultRetryPolicySpec    default retryPolicySpecKey conf value
   * @param remoteExceptionToRetry    The particular RemoteException to retry
   * @return the default retry policy.
   */
  public static RetryPolicy getDefaultRetryPolicy(
      Configuration conf,
      String retryPolicyEnabledKey,
      boolean defaultRetryPolicyEnabled,
      String retryPolicySpecKey,
      String defaultRetryPolicySpec,
      final String remoteExceptionToRetry
      ) {
    
    final RetryPolicy multipleLinearRandomRetry = 
        getMultipleLinearRandomRetry(
            conf, 
            retryPolicyEnabledKey, defaultRetryPolicyEnabled, 
            retryPolicySpecKey, defaultRetryPolicySpec
            );
    
    LOG.debug("multipleLinearRandomRetry = {}", multipleLinearRandomRetry);

    if (multipleLinearRandomRetry == null) {
      //no retry
      return RetryPolicies.TRY_ONCE_THEN_FAIL;
    } else {
      return new WrapperRetryPolicy(
          (MultipleLinearRandomRetry) multipleLinearRandomRetry,
          remoteExceptionToRetry);
    }
  }

  private static final class WrapperRetryPolicy implements RetryPolicy {
    private MultipleLinearRandomRetry multipleLinearRandomRetry;
    private String remoteExceptionToRetry;

    private WrapperRetryPolicy(
        final MultipleLinearRandomRetry multipleLinearRandomRetry,
        final String remoteExceptionToRetry) {
      this.multipleLinearRandomRetry = multipleLinearRandomRetry;
      this.remoteExceptionToRetry = remoteExceptionToRetry;
    }

    @Override
    public RetryAction shouldRetry(Exception e, int retries, int failovers,
        boolean isMethodIdempotent) throws Exception {
      if (e instanceof ServiceException) {
        //unwrap ServiceException
        final Throwable cause = e.getCause();
        if (cause != null && cause instanceof Exception) {
          e = (Exception)cause;
        }
      }

      //see (1) and (2) in the javadoc of this method.
      final RetryPolicy p;
      if (e instanceof RetriableException
          || RetryPolicies.getWrappedRetriableException(e) != null) {
        // RetriableException or RetriableException wrapped
        p = multipleLinearRandomRetry;
      } else if (e instanceof RemoteException) {
        final RemoteException re = (RemoteException)e;
        p = re.getClassName().equals(remoteExceptionToRetry)
            ? multipleLinearRandomRetry : RetryPolicies.TRY_ONCE_THEN_FAIL;
      } else if (e instanceof IOException || e instanceof ServiceException) {
        p = multipleLinearRandomRetry;
      } else { //non-IOException
        p = RetryPolicies.TRY_ONCE_THEN_FAIL;
      }

      LOG.debug("RETRY {}) policy={}", retries,
            p.getClass().getSimpleName(), e);

      return p.shouldRetry(e, retries, failovers, isMethodIdempotent);
    }

    /**
     * remoteExceptionToRetry is ignored as part of equals since it does not
     * affect connection failure handling.
     */
    @Override
    public boolean equals(final Object obj) {
      if (obj == this) {
        return true;
      } else {
        return (obj instanceof WrapperRetryPolicy)
            && this.multipleLinearRandomRetry
                .equals(((WrapperRetryPolicy) obj).multipleLinearRandomRetry);
      }
    }

    /**
     * Similarly, remoteExceptionToRetry is ignored as part of hashCode since it
     * does not affect connection failure handling.
     */
    @Override
    public int hashCode() {
      return multipleLinearRandomRetry.hashCode();
    }

    @Override
    public String toString() {
      return "RetryPolicy[" + multipleLinearRandomRetry + ", "
          + RetryPolicies.TRY_ONCE_THEN_FAIL.getClass().getSimpleName() + "]";
    }
  }

  /**
   * Return the MultipleLinearRandomRetry policy specified in the conf,
   * or null if the feature is disabled.
   * If the policy is specified in the conf but the policy cannot be parsed,
   * the default policy is returned.
   * 
   * Retry policy spec:
   *   N pairs of sleep-time and number-of-retries "s1,n1,s2,n2,..."
   * 
   * @param conf configuration.
   * @param retryPolicyEnabledKey     conf property key for enabling retry
   * @param defaultRetryPolicyEnabled default retryPolicyEnabledKey conf value 
   * @param retryPolicySpecKey        conf property key for retry policy spec
   * @param defaultRetryPolicySpec    default retryPolicySpecKey conf value
   * @return the MultipleLinearRandomRetry policy specified in the conf,
   *         or null if the feature is disabled.
   */
  public static RetryPolicy getMultipleLinearRandomRetry(
      Configuration conf,
      String retryPolicyEnabledKey,
      boolean defaultRetryPolicyEnabled,
      String retryPolicySpecKey,
      String defaultRetryPolicySpec
      ) {
    final boolean enabled = 
        conf.getBoolean(retryPolicyEnabledKey, defaultRetryPolicyEnabled);
    if (!enabled) {
      return null;
    }

    final String policy = conf.get(retryPolicySpecKey, defaultRetryPolicySpec);

    final RetryPolicy r = 
        RetryPolicies.MultipleLinearRandomRetry.parseCommaSeparatedString(
            policy);
    return (r != null) ? 
        r : 
        RetryPolicies.MultipleLinearRandomRetry.parseCommaSeparatedString(
        defaultRetryPolicySpec);
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AsyncCallHandler 源码

hadoop AtMostOnce 源码

hadoop CallReturn 源码

hadoop DefaultFailoverProxyProvider 源码

hadoop FailoverProxyProvider 源码

hadoop Idempotent 源码

hadoop LossyRetryInvocationHandler 源码

hadoop MultiException 源码

hadoop RetryInvocationHandler 源码

hadoop RetryPolicies 源码

0  赞