1 /**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19 package org.apache.hadoop.hbase.client.metrics;
20
21 import java.util.HashMap;
22 import java.util.Map;
23 import java.util.concurrent.atomic.AtomicLong;
24
25 import org.apache.commons.logging.Log;
26 import org.apache.commons.logging.LogFactory;
27 import org.apache.hadoop.hbase.classification.InterfaceAudience;
28
29 import com.google.common.collect.ImmutableMap;
30
31
32 /**
33 * Provides client-side metrics related to scan operations
34 * The data can be passed to mapreduce framework or other systems.
35 * We use atomic longs so that one thread can increment,
36 * while another atomically resets to zero after the values are reported
37 * to hadoop's counters.
38 *
39 * Some of these metrics are general for any client operation such as put
40 * However, there is no need for this. So they are defined under scan operation
41 * for now.
42 */
43 @InterfaceAudience.Private
44 public class ScanMetrics {
45
46
47 private static final Log LOG = LogFactory.getLog(ScanMetrics.class);
48
49 /**
50 * Hash to hold the String -> Atomic Long mappings.
51 */
52 private final Map<String, AtomicLong> counters = new HashMap<String, AtomicLong>();
53
54 // AtomicLongs to hold the metrics values. These are all updated through ClientScanner and
55 // ScannerCallable. They are atomic longs so that atomic getAndSet can be used to reset the
56 // values after progress is passed to hadoop's counters.
57
58
59 /**
60 * number of RPC calls
61 */
62 public final AtomicLong countOfRPCcalls = createCounter("RPC_CALLS");
63
64 /**
65 * number of remote RPC calls
66 */
67 public final AtomicLong countOfRemoteRPCcalls = createCounter("REMOTE_RPC_CALLS");
68
69 /**
70 * sum of milliseconds between sequential next calls
71 */
72 public final AtomicLong sumOfMillisSecBetweenNexts = createCounter("MILLIS_BETWEEN_NEXTS");
73
74 /**
75 * number of NotServingRegionException caught
76 */
77 public final AtomicLong countOfNSRE = createCounter("NOT_SERVING_REGION_EXCEPTION");
78
79 /**
80 * number of bytes in Result objects from region servers
81 */
82 public final AtomicLong countOfBytesInResults = createCounter("BYTES_IN_RESULTS");
83
84 /**
85 * number of bytes in Result objects from remote region servers
86 */
87 public final AtomicLong countOfBytesInRemoteResults = createCounter("BYTES_IN_REMOTE_RESULTS");
88
89 /**
90 * number of regions
91 */
92 public final AtomicLong countOfRegions = createCounter("REGIONS_SCANNED");
93
94 /**
95 * number of RPC retries
96 */
97 public final AtomicLong countOfRPCRetries = createCounter("RPC_RETRIES");
98
99 /**
100 * number of remote RPC retries
101 */
102 public final AtomicLong countOfRemoteRPCRetries = createCounter("REMOTE_RPC_RETRIES");
103
104 /**
105 * constructor
106 */
107 public ScanMetrics() {
108 }
109
110 private AtomicLong createCounter(String counterName) {
111 AtomicLong c = new AtomicLong(0);
112 counters.put(counterName, c);
113 return c;
114 }
115
116 public void setCounter(String counterName, long value) {
117 AtomicLong c = this.counters.get(counterName);
118 if (c != null) {
119 c.set(value);
120 }
121 }
122
123 /**
124 * Get all of the values since the last time this function was called.
125 *
126 * Calling this function will reset all AtomicLongs in the instance back to 0.
127 *
128 * @return A Map of String -> Long for metrics
129 */
130 public Map<String, Long> getMetricsMap() {
131 //Create a builder
132 ImmutableMap.Builder<String, Long> builder = ImmutableMap.builder();
133 //For every entry add the value and reset the AtomicLong back to zero
134 for (Map.Entry<String, AtomicLong> e : this.counters.entrySet()) {
135 builder.put(e.getKey(), e.getValue().getAndSet(0));
136 }
137 //Build the immutable map so that people can't mess around with it.
138 return builder.build();
139 }
140
141 }