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.hbase.procedure;
19
20 import java.io.IOException;
21
22 import org.apache.hadoop.hbase.classification.InterfaceAudience;
23 import org.apache.hadoop.hbase.classification.InterfaceStability;
24 import org.apache.hadoop.hbase.Stoppable;
25 import org.apache.hadoop.hbase.master.MasterServices;
26 import org.apache.hadoop.hbase.master.MetricsMaster;
27 import org.apache.hadoop.hbase.master.HMaster;
28 import org.apache.hadoop.hbase.master.snapshot.SnapshotManager;
29 import org.apache.hadoop.hbase.regionserver.HRegionServer;
30 import org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager;
31 import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.ProcedureDescription;
32 import org.apache.zookeeper.KeeperException;
33
34 /**
35 * A life-cycle management interface for globally barriered procedures on master.
36 * See the following doc on details of globally barriered procedure:
37 * https://issues.apache.org/jira/secure/attachment/12555103/121127-global-barrier-proc.pdf
38 *
39 * To implement a custom globally barriered procedure, user needs to extend two classes:
40 * {@link MasterProcedureManager} and {@link RegionServerProcedureManager}. Implementation of
41 * {@link MasterProcedureManager} is loaded into {@link HMaster} process via configuration
42 * parameter 'hbase.procedure.master.classes', while implementation of
43 * {@link RegionServerProcedureManager} is loaded into {@link HRegionServer} process via
44 * configuration parameter 'hbase.procedure.regionserver.classes'.
45 *
46 * An example of globally barriered procedure implementation is {@link SnapshotManager} and
47 * {@link RegionServerSnapshotManager}.
48 *
49 * A globally barriered procedure is identified by its signature (usually it is the name of the
50 * procedure znode). During the initialization phase, the initialize methods are called by both
51 * {@link HMaster} and {@link HRegionServer} witch create the procedure znode and register the
52 * listeners. A procedure can be triggered by its signature and an instant name (encapsulated in
53 * a {@link ProcedureDescription} object). When the servers are shutdown, the stop methods on both
54 * classes are called to clean up the data associated with the procedure.
55 */
56 @InterfaceAudience.Private
57 @InterfaceStability.Evolving
58 public abstract class MasterProcedureManager extends ProcedureManager implements
59 Stoppable {
60 /**
61 * Initialize a globally barriered procedure for master.
62 *
63 * @param master Master service interface
64 * @throws KeeperException
65 * @throws IOException
66 * @throws UnsupportedOperationException
67 */
68 public abstract void initialize(MasterServices master, MetricsMaster metricsMaster)
69 throws KeeperException, IOException, UnsupportedOperationException;
70
71 /**
72 * Execute a distributed procedure on cluster
73 *
74 * @param desc Procedure description
75 * @throws IOException
76 */
77 public abstract void execProcedure(ProcedureDescription desc) throws IOException;
78
79 /**
80 * Check if the procedure is finished successfully
81 *
82 * @param desc Procedure description
83 * @return true if the specified procedure is finished successfully
84 * @throws IOException
85 */
86 public abstract boolean isProcedureDone(ProcedureDescription desc) throws IOException;
87 }