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 */
018package org.apache.hadoop.hbase.client.metrics;
019
020import java.util.HashMap;
021import java.util.Map;
022import java.util.concurrent.atomic.AtomicLong;
023
024import org.apache.yetus.audience.InterfaceAudience;
025
026import org.apache.hbase.thirdparty.com.google.common.collect.ImmutableMap;
027
028/**
029 * Provides server side metrics related to scan operations.
030 */
031@InterfaceAudience.Public
032public class ServerSideScanMetrics {
033  /**
034   * Hash to hold the String -> Atomic Long mappings for each metric
035   */
036  private final Map<String, AtomicLong> counters = new HashMap<>();
037
038  /**
039   * Create a new counter with the specified name
040   * @param counterName
041   * @return {@link AtomicLong} instance for the counter with counterName
042   */
043  protected AtomicLong createCounter(String counterName) {
044    AtomicLong c = new AtomicLong(0);
045    counters.put(counterName, c);
046    return c;
047  }
048
049  public static final String COUNT_OF_ROWS_SCANNED_KEY_METRIC_NAME = "ROWS_SCANNED";
050  public static final String COUNT_OF_ROWS_FILTERED_KEY_METRIC_NAME = "ROWS_FILTERED";
051
052  /**
053   * @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0
054   *             (<a href="https://issues.apache.org/jira/browse/HBASE-17886">HBASE-17886</a>).
055   *             Use {@link #COUNT_OF_ROWS_SCANNED_KEY_METRIC_NAME}.
056   */
057  @Deprecated
058  public static final String COUNT_OF_ROWS_SCANNED_KEY = COUNT_OF_ROWS_SCANNED_KEY_METRIC_NAME;
059
060  /**
061   * @deprecated As of release 2.0.0, this will be removed in HBase 3.0.0
062   *             (<a href="https://issues.apache.org/jira/browse/HBASE-17886">HBASE-17886</a>).
063   *             Use {@link #COUNT_OF_ROWS_FILTERED_KEY_METRIC_NAME}.
064   */
065  @Deprecated
066  public static final String COUNT_OF_ROWS_FILTERED_KEY = COUNT_OF_ROWS_FILTERED_KEY_METRIC_NAME;
067
068  /**
069   * number of rows filtered during scan RPC
070   */
071  public final AtomicLong countOfRowsFiltered = createCounter(COUNT_OF_ROWS_FILTERED_KEY_METRIC_NAME);
072
073  /**
074   * number of rows scanned during scan RPC. Not every row scanned will be returned to the client
075   * since rows may be filtered.
076   */
077  public final AtomicLong countOfRowsScanned = createCounter(COUNT_OF_ROWS_SCANNED_KEY_METRIC_NAME);
078
079  /**
080   * @param counterName
081   * @param value
082   */
083  public void setCounter(String counterName, long value) {
084    AtomicLong c = this.counters.get(counterName);
085    if (c != null) {
086      c.set(value);
087    }
088  }
089
090  /**
091   * @param counterName
092   * @return true if a counter exists with the counterName
093   */
094  public boolean hasCounter(String counterName) {
095    return this.counters.containsKey(counterName);
096  }
097
098  /**
099   * @param counterName
100   * @return {@link AtomicLong} instance for this counter name, null if counter does not exist.
101   */
102  public AtomicLong getCounter(String counterName) {
103    return this.counters.get(counterName);
104  }
105
106  /**
107   * @param counterName
108   * @param delta
109   */
110  public void addToCounter(String counterName, long delta) {
111    AtomicLong c = this.counters.get(counterName);
112    if (c != null) {
113      c.addAndGet(delta);
114    }
115  }
116
117  /**
118   * Get all of the values since the last time this function was called. Calling this function will
119   * reset all AtomicLongs in the instance back to 0.
120   * @return A Map of String -&gt; Long for metrics
121   */
122  public Map<String, Long> getMetricsMap() {
123    return getMetricsMap(true);
124  }
125
126  /**
127   * Get all of the values. If reset is true, we will reset the all AtomicLongs back to 0.
128   * @param reset whether to reset the AtomicLongs to 0.
129   * @return A Map of String -&gt; Long for metrics
130   */
131  public Map<String, Long> getMetricsMap(boolean reset) {
132    // Create a builder
133    ImmutableMap.Builder<String, Long> builder = ImmutableMap.builder();
134    for (Map.Entry<String, AtomicLong> e : this.counters.entrySet()) {
135      long value = reset ? e.getValue().getAndSet(0) : e.getValue().get();
136      builder.put(e.getKey(), value);
137    }
138    // Build the immutable map so that people can't mess around with it.
139    return builder.build();
140  }
141}