001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.procedure;
019
020import java.io.IOException;
021import org.apache.hadoop.hbase.Stoppable;
022import org.apache.hadoop.hbase.master.MasterServices;
023import org.apache.hadoop.hbase.master.MetricsMaster;
024import org.apache.hadoop.hbase.security.User;
025import org.apache.hadoop.hbase.security.access.AccessChecker;
026import org.apache.yetus.audience.InterfaceAudience;
027import org.apache.zookeeper.KeeperException;
028
029import org.apache.hadoop.hbase.shaded.protobuf.generated.HBaseProtos.ProcedureDescription;
030
031/**
032 * A life-cycle management interface for globally barriered procedures on master. See the following
033 * doc on details of globally barriered procedure:
034 * https://issues.apache.org/jira/secure/attachment/12555103/121127-global-barrier-proc.pdf To
035 * implement a custom globally barriered procedure, user needs to extend two classes:
036 * {@link MasterProcedureManager} and {@link RegionServerProcedureManager}. Implementation of
037 * {@link MasterProcedureManager} is loaded into {@link org.apache.hadoop.hbase.master.HMaster}
038 * process via configuration parameter 'hbase.procedure.master.classes', while implementation of
039 * {@link RegionServerProcedureManager} is loaded into
040 * {@link org.apache.hadoop.hbase.regionserver.HRegionServer} process via configuration parameter
041 * 'hbase.procedure.regionserver.classes'. An example of globally barriered procedure implementation
042 * is {@link org.apache.hadoop.hbase.master.snapshot.SnapshotManager} and
043 * {@link org.apache.hadoop.hbase.regionserver.snapshot.RegionServerSnapshotManager}. A globally
044 * barriered procedure is identified by its signature (usually it is the name of the procedure
045 * znode). During the initialization phase, the initialize methods are called by both
046 * {@link org.apache.hadoop.hbase.master.HMaster} and
047 * {@link org.apache.hadoop.hbase.regionserver.HRegionServer} which create the procedure znode and
048 * register the listeners. A procedure can be triggered by its signature and an instant name
049 * (encapsulated in a {@link ProcedureDescription} object). When the servers are shutdown, the stop
050 * methods on both classes are called to clean up the data associated with the procedure.
051 */
052@InterfaceAudience.Private
053public abstract class MasterProcedureManager extends ProcedureManager implements Stoppable {
054  /**
055   * Initialize a globally barriered procedure for master.
056   * @param master Master service interface
057   */
058  public abstract void initialize(MasterServices master, MetricsMaster metricsMaster)
059    throws KeeperException, IOException, UnsupportedOperationException;
060
061  /**
062   * Execute a distributed procedure on cluster
063   * @param desc Procedure description
064   */
065  public void execProcedure(ProcedureDescription desc) throws IOException {
066  }
067
068  /**
069   * Execute a distributed procedure on cluster with return data.
070   * @param desc Procedure description
071   * @return data returned from the procedure execution, null if no data
072   */
073  public byte[] execProcedureWithRet(ProcedureDescription desc) throws IOException {
074    return null;
075  }
076
077  /**
078   * Check for required permissions before executing the procedure.
079   * @throws IOException if permissions requirements are not met.
080   */
081  public abstract void checkPermissions(ProcedureDescription desc, AccessChecker accessChecker,
082    User user) throws IOException;
083
084  /**
085   * Check if the procedure is finished successfully
086   * @param desc Procedure description
087   * @return true if the specified procedure is finished successfully
088   */
089  public abstract boolean isProcedureDone(ProcedureDescription desc) throws IOException;
090}