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.hadoop.hbase.classification.InterfaceAudience;
26 import org.apache.hadoop.hbase.classification.InterfaceStability;
27
28 import com.google.common.collect.ImmutableMap;
29
30
31 /**
32 * Provides client-side metrics related to scan operations.
33 * The data can be passed to mapreduce framework or other systems.
34 * We use atomic longs so that one thread can increment,
35 * while another atomically resets to zero after the values are reported
36 * to hadoop's counters.
37 *
38 * Some of these metrics are general for any client operation such as put
39 * However, there is no need for this. So they are defined under scan operation
40 * for now.
41 */
42 @InterfaceAudience.Public
43 @InterfaceStability.Evolving
44 public class ScanMetrics {
45
46 /**
47 * Hash to hold the String -> Atomic Long mappings.
48 */
49 private final Map<String, AtomicLong> counters = new HashMap<String, AtomicLong>();
50
51 // AtomicLongs to hold the metrics values. These are all updated through ClientScanner and
52 // ScannerCallable. They are atomic longs so that atomic getAndSet can be used to reset the
53 // values after progress is passed to hadoop's counters.
54
55
56 /**
57 * number of RPC calls
58 */
59 public final AtomicLong countOfRPCcalls = createCounter("RPC_CALLS");
60
61 /**
62 * number of remote RPC calls
63 */
64 public final AtomicLong countOfRemoteRPCcalls = createCounter("REMOTE_RPC_CALLS");
65
66 /**
67 * sum of milliseconds between sequential next calls
68 */
69 public final AtomicLong sumOfMillisSecBetweenNexts = createCounter("MILLIS_BETWEEN_NEXTS");
70
71 /**
72 * number of NotServingRegionException caught
73 */
74 public final AtomicLong countOfNSRE = createCounter("NOT_SERVING_REGION_EXCEPTION");
75
76 /**
77 * number of bytes in Result objects from region servers
78 */
79 public final AtomicLong countOfBytesInResults = createCounter("BYTES_IN_RESULTS");
80
81 /**
82 * number of bytes in Result objects from remote region servers
83 */
84 public final AtomicLong countOfBytesInRemoteResults = createCounter("BYTES_IN_REMOTE_RESULTS");
85
86 /**
87 * number of regions
88 */
89 public final AtomicLong countOfRegions = createCounter("REGIONS_SCANNED");
90
91 /**
92 * number of RPC retries
93 */
94 public final AtomicLong countOfRPCRetries = createCounter("RPC_RETRIES");
95
96 /**
97 * number of remote RPC retries
98 */
99 public final AtomicLong countOfRemoteRPCRetries = createCounter("REMOTE_RPC_RETRIES");
100
101 /**
102 * constructor
103 */
104 public ScanMetrics() {
105 }
106
107 private AtomicLong createCounter(String counterName) {
108 AtomicLong c = new AtomicLong(0);
109 counters.put(counterName, c);
110 return c;
111 }
112
113 public void setCounter(String counterName, long value) {
114 AtomicLong c = this.counters.get(counterName);
115 if (c != null) {
116 c.set(value);
117 }
118 }
119
120 /**
121 * Get all of the values since the last time this function was called.
122 *
123 * Calling this function will reset all AtomicLongs in the instance back to 0.
124 *
125 * @return A Map of String -> Long for metrics
126 */
127 public Map<String, Long> getMetricsMap() {
128 //Create a builder
129 ImmutableMap.Builder<String, Long> builder = ImmutableMap.builder();
130 //For every entry add the value and reset the AtomicLong back to zero
131 for (Map.Entry<String, AtomicLong> e : this.counters.entrySet()) {
132 builder.put(e.getKey(), e.getValue().getAndSet(0));
133 }
134 //Build the immutable map so that people can't mess around with it.
135 return builder.build();
136 }
137
138 }