001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.hadoop.hdfs;
019    
020    import java.util.concurrent.atomic.AtomicLong;
021    
022    /**
023     * The client-side metrics for hedged read feature.
024     * This class has a number of metrics variables that are publicly accessible,
025     * we can grab them from client side, like HBase.
026     */
027    public class DFSHedgedReadMetrics {
028      public final AtomicLong hedgedReadOps = new AtomicLong();
029      public final AtomicLong hedgedReadOpsWin = new AtomicLong();
030      public final AtomicLong hedgedReadOpsInCurThread = new AtomicLong();
031    
032      public void incHedgedReadOps() {
033        hedgedReadOps.incrementAndGet();
034      }
035    
036      public void incHedgedReadOpsInCurThread() {
037        hedgedReadOpsInCurThread.incrementAndGet();
038      }
039    
040      public void incHedgedReadWins() {
041        hedgedReadOpsWin.incrementAndGet();
042      }
043    
044      public long getHedgedReadOps() {
045        return hedgedReadOps.longValue();
046      }
047    
048      public long getHedgedReadOpsInCurThread() {
049        return hedgedReadOpsInCurThread.longValue();
050      }
051    
052      public long getHedgedReadWins() {
053        return hedgedReadOpsWin.longValue();
054      }
055    }