1 /*
2 *
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 */
19
20 package org.apache.hadoop.hbase.coprocessor;
21
22 import java.util.concurrent.ConcurrentMap;
23
24 import org.apache.hadoop.hbase.CoprocessorEnvironment;
25 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
26 import org.apache.hadoop.hbase.HRegionInfo;
27 import org.apache.hadoop.hbase.classification.InterfaceAudience;
28 import org.apache.hadoop.hbase.classification.InterfaceStability;
29 import org.apache.hadoop.hbase.metrics.MetricRegistry;
30 import org.apache.hadoop.hbase.regionserver.Region;
31 import org.apache.hadoop.hbase.regionserver.RegionServerServices;
32
33 @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
34 @InterfaceStability.Evolving
35 public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment {
36 /** @return the region associated with this coprocessor */
37 Region getRegion();
38
39 /** @return region information for the region this coprocessor is running on */
40 HRegionInfo getRegionInfo();
41
42 /** @return reference to the region server services */
43 RegionServerServices getRegionServerServices();
44
45 /** @return shared data between all instances of this coprocessor */
46 ConcurrentMap<String, Object> getSharedData();
47
48 /**
49 * Returns a MetricRegistry that can be used to track metrics at the region server level. All
50 * metrics tracked at this level will be shared by all the coprocessor instances
51 * of the same class in the same region server process. Note that there will be one
52 * region coprocessor environment per region in the server, but all of these instances will share
53 * the same MetricRegistry. The metric instances (like Counter, Timer, etc) will also be shared
54 * among all of the region coprocessor instances.
55 *
56 * <p>See ExampleRegionObserverWithMetrics class in the hbase-examples modules to see examples of how
57 * metrics can be instantiated and used.</p>
58 * @return A MetricRegistry for the coprocessor class to track and export metrics.
59 */
60 // Note: we are not exposing getMetricRegistryForRegion(). per-region metrics are already costly
61 // so we do not want to allow coprocessors to export metrics at the region level. We can allow
62 // getMetricRegistryForTable() to allow coprocessors to track metrics per-table, per-regionserver.
63 MetricRegistry getMetricRegistryForRegionServer();
64
65
66 }