/*
* Copyright 2011 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.coprocessor;
import org.apache.hadoop.hbase.*;
import java.io.IOException;
/**
* Defines coprocessor hooks for interacting with operations on the
* {@link org.apache.hadoop.hbase.master.HMaster} process.
*/
public interface MasterObserver extends Coprocessor {
/**
* Called before a new table is created by
* {@link org.apache.hadoop.hbase.master.HMaster}.
* It can't bypass the default action, e.g., ctx.bypass() won't have effect.
* @param ctx the environment to interact with the framework and master
* @param desc the HTableDescriptor for the table
* @param regions the initial regions created for the table
* @throws IOException
*/
void preCreateTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
HTableDescriptor desc, HRegionInfo[] regions) throws IOException;
/**
* Called after the createTable operation has been requested.
* @param ctx the environment to interact with the framework and master
* @param desc the HTableDescriptor for the table
* @param regions the initial regions created for the table
* @throws IOException
*/
void postCreateTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
HTableDescriptor desc, HRegionInfo[] regions) throws IOException;
/**
* Called before {@link org.apache.hadoop.hbase.master.HMaster} deletes a
* table
* It can't bypass the default action, e.g., ctx.bypass() won't have effect.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void preDeleteTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte[] tableName) throws IOException;
/**
* Called after the deleteTable operation has been requested.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void postDeleteTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte[] tableName) throws IOException;
/**
* Called prior to modifying a table's properties.
* It can't bypass the default action, e.g., ctx.bypass() won't have effect.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param htd the HTableDescriptor
*/
void preModifyTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName, HTableDescriptor htd) throws IOException;
/**
* Called after the modifyTable operation has been requested.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param htd the HTableDescriptor
*/
void postModifyTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName, HTableDescriptor htd) throws IOException;
/**
* Called prior to adding a new column family to the table.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param column the HColumnDescriptor
*/
void preAddColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte[] tableName, HColumnDescriptor column) throws IOException;
/**
* Called after the new column family has been created.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param column the HColumnDescriptor
*/
void postAddColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte[] tableName, HColumnDescriptor column) throws IOException;
/**
* Called prior to modifying a column family's attributes.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param descriptor the HColumnDescriptor
*/
void preModifyColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte [] tableName, HColumnDescriptor descriptor) throws IOException;
/**
* Called after the column family has been updated.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param descriptor the HColumnDescriptor
*/
void postModifyColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
byte[] tableName, HColumnDescriptor descriptor) throws IOException;
/**
* Called prior to deleting the entire column family.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param c the column
*/
void preDeleteColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte [] tableName, final byte[] c) throws IOException;
/**
* Called after the column family has been deleted.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
* @param c the column
*/
void postDeleteColumn(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte [] tableName, final byte[] c) throws IOException;
/**
* Called prior to enabling a table.
* It can't bypass the default action, e.g., ctx.bypass() won't have effect.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void preEnableTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName) throws IOException;
/**
* Called after the enableTable operation has been requested.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void postEnableTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName) throws IOException;
/**
* Called prior to disabling a table.
* It can't bypass the default action, e.g., ctx.bypass() won't have effect.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void preDisableTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName) throws IOException;
/**
* Called after the disableTable operation has been requested.
* @param ctx the environment to interact with the framework and master
* @param tableName the name of the table
*/
void postDisableTable(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final byte[] tableName) throws IOException;
/**
* Called prior to moving a given region from one region server to another.
* @param ctx the environment to interact with the framework and master
* @param region the HRegionInfo
* @param srcServer the source ServerName
* @param destServer the destination ServerName
*/
void preMove(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo region, final ServerName srcServer,
final ServerName destServer)
throws IOException;
/**
* Called after the region move has been requested.
* @param ctx the environment to interact with the framework and master
* @param region the HRegionInfo
* @param srcServer the source ServerName
* @param destServer the destination ServerName
*/
void postMove(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo region, final ServerName srcServer,
final ServerName destServer)
throws IOException;
/**
* Called prior to assigning a specific region.
* @param ctx the environment to interact with the framework and master
* @param regionInfo the regionInfo of the region
*/
void preAssign(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo regionInfo) throws IOException;
/**
* Called after the region assignment has been requested.
* @param ctx the environment to interact with the framework and master
* @param regionInfo the regionInfo of the region
*/
void postAssign(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo regionInfo) throws IOException;
/**
* Called prior to unassigning a given region.
* @param ctx the environment to interact with the framework and master
* @param regionInfo
* @param force whether to force unassignment or not
*/
void preUnassign(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo regionInfo, final boolean force) throws IOException;
/**
* Called after the region unassignment has been requested.
* @param ctx the environment to interact with the framework and master
* @param regionInfo
* @param force whether to force unassignment or not
*/
void postUnassign(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final HRegionInfo regionInfo, final boolean force) throws IOException;
/**
* Called prior to requesting rebalancing of the cluster regions, though after
* the initial checks for regions in transition and the balance switch flag.
* @param ctx the environment to interact with the framework and master
*/
void preBalance(final ObserverContext<MasterCoprocessorEnvironment> ctx)
throws IOException;
/**
* Called after the balancing plan has been submitted.
* @param ctx the environment to interact with the framework and master
*/
void postBalance(final ObserverContext<MasterCoprocessorEnvironment> ctx)
throws IOException;
/**
* Called prior to modifying the flag used to enable/disable region balancing.
* @param ctx the coprocessor instance's environment
* @param newValue the new flag value submitted in the call
*/
boolean preBalanceSwitch(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final boolean newValue) throws IOException;
/**
* Called after the flag to enable/disable balancing has changed.
* @param ctx the coprocessor instance's environment
* @param oldValue the previously set balanceSwitch value
* @param newValue the newly set balanceSwitch value
*/
void postBalanceSwitch(final ObserverContext<MasterCoprocessorEnvironment> ctx,
final boolean oldValue, final boolean newValue) throws IOException;
/**
* Called prior to shutting down the full HBase cluster, including this
* {@link org.apache.hadoop.hbase.master.HMaster} process.
*/
void preShutdown(final ObserverContext<MasterCoprocessorEnvironment> ctx)
throws IOException;
/**
* Called immediately prior to stopping this
* {@link org.apache.hadoop.hbase.master.HMaster} process.
*/
void preStopMaster(final ObserverContext<MasterCoprocessorEnvironment> ctx)
throws IOException;
/**
* Called immediately after an active master instance has completed
* initialization. Will not be called on standby master instances unless
* they take over the active role.
*/
void postStartMaster(final ObserverContext<MasterCoprocessorEnvironment> ctx)
throws IOException;
}