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 | package org.apache.hadoop.metrics.util; |
---|
19 | |
---|
20 | import org.apache.hadoop.metrics.MetricsRecord; |
---|
21 | import org.apache.hadoop.util.StringUtils; |
---|
22 | |
---|
23 | import org.apache.commons.logging.Log; |
---|
24 | import org.apache.commons.logging.LogFactory; |
---|
25 | |
---|
26 | /** |
---|
27 | * The MetricsIntValue class is for a metric that is not time varied |
---|
28 | * but changes only when it is set. |
---|
29 | * Each time its value is set, it is published only *once* at the next update |
---|
30 | * call. |
---|
31 | * |
---|
32 | */ |
---|
33 | public class MetricsIntValue extends MetricsBase { |
---|
34 | |
---|
35 | private static final Log LOG = |
---|
36 | LogFactory.getLog("org.apache.hadoop.metrics.util"); |
---|
37 | |
---|
38 | private int value; |
---|
39 | private boolean changed; |
---|
40 | |
---|
41 | |
---|
42 | /** |
---|
43 | * Constructor - create a new metric |
---|
44 | * @param nam the name of the metrics to be used to publish the metric |
---|
45 | * @param registry - where the metrics object will be registered |
---|
46 | */ |
---|
47 | public MetricsIntValue(final String nam, final MetricsRegistry registry, final String description) { |
---|
48 | super(nam, description); |
---|
49 | value = 0; |
---|
50 | changed = false; |
---|
51 | registry.add(nam, this); |
---|
52 | } |
---|
53 | |
---|
54 | /** |
---|
55 | * Constructor - create a new metric |
---|
56 | * @param nam the name of the metrics to be used to publish the metric |
---|
57 | * @param registry - where the metrics object will be registered |
---|
58 | * A description of {@link #NO_DESCRIPTION} is used |
---|
59 | */ |
---|
60 | public MetricsIntValue(final String nam, MetricsRegistry registry) { |
---|
61 | this(nam, registry, NO_DESCRIPTION); |
---|
62 | } |
---|
63 | |
---|
64 | |
---|
65 | |
---|
66 | /** |
---|
67 | * Set the value |
---|
68 | * @param newValue |
---|
69 | */ |
---|
70 | public synchronized void set(final int newValue) { |
---|
71 | value = newValue; |
---|
72 | changed = true; |
---|
73 | } |
---|
74 | |
---|
75 | /** |
---|
76 | * Get value |
---|
77 | * @return the value last set |
---|
78 | */ |
---|
79 | public synchronized int get() { |
---|
80 | return value; |
---|
81 | } |
---|
82 | |
---|
83 | |
---|
84 | /** |
---|
85 | * Push the metric to the mr. |
---|
86 | * The metric is pushed only if it was updated since last push |
---|
87 | * |
---|
88 | * Note this does NOT push to JMX |
---|
89 | * (JMX gets the info via {@link #get()} |
---|
90 | * |
---|
91 | * @param mr |
---|
92 | */ |
---|
93 | public synchronized void pushMetric(final MetricsRecord mr) { |
---|
94 | if (changed) { |
---|
95 | try { |
---|
96 | mr.setMetric(getName(), value); |
---|
97 | } catch (Exception e) { |
---|
98 | LOG.info("pushMetric failed for " + getName() + "\n" + |
---|
99 | StringUtils.stringifyException(e)); |
---|
100 | } |
---|
101 | } |
---|
102 | changed = false; |
---|
103 | } |
---|
104 | } |
---|