hadoop AbfsClientThrottlingIntercept 源码

haddop AbfsClientThrottlingIntercept 代码

文件路径：/hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/services/AbfsClientThrottlingIntercept.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.fs.azurebfs.services;

import java.net.HttpURLConnection;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.hadoop.fs.azurebfs.AbfsStatistic;
import org.apache.hadoop.fs.azurebfs.constants.HttpHeaderConfigurations;

/**
 * Throttles Azure Blob File System read and write operations to achieve maximum
 * throughput by minimizing errors.  The errors occur when the account ingress
 * or egress limits are exceeded and the server-side throttles requests.
 * Server-side throttling causes the retry policy to be used, but the retry
 * policy sleeps for long periods of time causing the total ingress or egress
 * throughput to be as much as 35% lower than optimal.  The retry policy is also
 * after the fact, in that it applies after a request fails.  On the other hand,
 * the client-side throttling implemented here happens before requests are made
 * and sleeps just enough to minimize errors, allowing optimal ingress and/or
 * egress throughput.
 */
public final class AbfsClientThrottlingIntercept {
  private static final Logger LOG = LoggerFactory.getLogger(
      AbfsClientThrottlingIntercept.class);
  private static final String RANGE_PREFIX = "bytes=";
  private static AbfsClientThrottlingIntercept singleton = null;
  private AbfsClientThrottlingAnalyzer readThrottler = null;
  private AbfsClientThrottlingAnalyzer writeThrottler = null;
  private static boolean isAutoThrottlingEnabled = false;

  // Hide default constructor
  private AbfsClientThrottlingIntercept() {
    readThrottler = new AbfsClientThrottlingAnalyzer("read");
    writeThrottler = new AbfsClientThrottlingAnalyzer("write");
  }

  public static synchronized void initializeSingleton(boolean enableAutoThrottling) {
    if (!enableAutoThrottling) {
      return;
    }
    if (singleton == null) {
      singleton = new AbfsClientThrottlingIntercept();
      isAutoThrottlingEnabled = true;
      LOG.debug("Client-side throttling is enabled for the ABFS file system.");
    }
  }

  static void updateMetrics(AbfsRestOperationType operationType,
                            AbfsHttpOperation abfsHttpOperation) {
    if (!isAutoThrottlingEnabled || abfsHttpOperation == null) {
      return;
    }

    int status = abfsHttpOperation.getStatusCode();
    long contentLength = 0;
    // If the socket is terminated prior to receiving a response, the HTTP
    // status may be 0 or -1.  A status less than 200 or greater than or equal
    // to 500 is considered an error.
    boolean isFailedOperation = (status < HttpURLConnection.HTTP_OK
        || status >= HttpURLConnection.HTTP_INTERNAL_ERROR);

    switch (operationType) {
      case Append:
        contentLength = abfsHttpOperation.getBytesSent();
        if (contentLength > 0) {
          singleton.writeThrottler.addBytesTransferred(contentLength,
              isFailedOperation);
        }
        break;
      case ReadFile:
        String range = abfsHttpOperation.getConnection().getRequestProperty(HttpHeaderConfigurations.RANGE);
        contentLength = getContentLengthIfKnown(range);
        if (contentLength > 0) {
          singleton.readThrottler.addBytesTransferred(contentLength,
              isFailedOperation);
        }
        break;
      default:
        break;
    }
  }

  /**
   * Called before the request is sent.  Client-side throttling
   * uses this to suspend the request, if necessary, to minimize errors and
   * maximize throughput.
   */
  static void sendingRequest(AbfsRestOperationType operationType,
      AbfsCounters abfsCounters) {
    if (!isAutoThrottlingEnabled) {
      return;
    }

    switch (operationType) {
      case ReadFile:
        if (singleton.readThrottler.suspendIfNecessary()
            && abfsCounters != null) {
          abfsCounters.incrementCounter(AbfsStatistic.READ_THROTTLES, 1);
        }
        break;
      case Append:
        if (singleton.writeThrottler.suspendIfNecessary()
            && abfsCounters != null) {
          abfsCounters.incrementCounter(AbfsStatistic.WRITE_THROTTLES, 1);
        }
        break;
      default:
        break;
    }
  }

  private static long getContentLengthIfKnown(String range) {
    long contentLength = 0;
    // Format is "bytes=%d-%d"
    if (range != null && range.startsWith(RANGE_PREFIX)) {
      String[] offsets = range.substring(RANGE_PREFIX.length()).split("-");
      if (offsets.length == 2) {
        contentLength = Long.parseLong(offsets[1]) - Long.parseLong(offsets[0])
                + 1;
      }
    }
    return contentLength;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AbfsAclHelper 源码

hadoop AbfsClient 源码

hadoop AbfsClientContext 源码

hadoop AbfsClientContextBuilder 源码

hadoop AbfsClientRenameResult 源码

hadoop AbfsClientThrottlingAnalyzer 源码

hadoop AbfsCounters 源码

hadoop AbfsErrors 源码

hadoop AbfsHttpHeader 源码

hadoop AbfsHttpOperation 源码