org.apache.hudi.org.apache.hadoop.hbase.coprocessor.RegionServerObserver Maven / Gradle / Ivy
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*
* 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 java.io.IOException;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.replication.ReplicationEndpoint;
import org.apache.yetus.audience.InterfaceAudience;
import org.apache.yetus.audience.InterfaceStability;
/**
* Defines coprocessor hooks for interacting with operations on the
* {@link org.apache.hadoop.hbase.regionserver.HRegionServer} process.
*
* Since most implementations will be interested in only a subset of hooks, this class uses
* 'default' functions to avoid having to add unnecessary overrides. When the functions are
* non-empty, it's simply to satisfy the compiler by returning value of expected (non-void) type.
* It is done in a way that these default definitions act as no-op. So our suggestion to
* implementation would be to not call these 'default' methods from overrides.
*
*
* Exception Handling
* For all functions, exception handling is done as follows:
*
* - Exceptions of type {@link IOException} are reported back to client.
* - For any other kind of exception:
*
* - If the configuration {@link CoprocessorHost#ABORT_ON_ERROR_KEY} is set to true, then
* the server aborts.
* - Otherwise, coprocessor is removed from the server and
* {@link org.apache.hadoop.hbase.DoNotRetryIOException} is returned to the client.
*
*
*
*/
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface RegionServerObserver {
/**
* Called before stopping region server.
* @param ctx the environment to interact with the framework and region server.
*/
default void preStopRegionServer(
final ObserverContext ctx) throws IOException {}
/**
* This will be called before executing user request to roll a region server WAL.
* @param ctx the environment to interact with the framework and region server.
*/
default void preRollWALWriterRequest(
final ObserverContext ctx)
throws IOException {}
/**
* This will be called after executing user request to roll a region server WAL.
* @param ctx the environment to interact with the framework and region server.
*/
default void postRollWALWriterRequest(
final ObserverContext ctx)
throws IOException {}
/**
* This will be called after the replication endpoint is instantiated.
* @param ctx the environment to interact with the framework and region server.
* @param endpoint - the base endpoint for replication
* @return the endpoint to use during replication.
*/
default ReplicationEndpoint postCreateReplicationEndPoint(
ObserverContext ctx, ReplicationEndpoint endpoint) {
return endpoint;
}
// TODO remove below 2 hooks when we implement AC as a core impl than a CP impl.
/**
* This will be called before executing replication request to shipping log entries.
* @param ctx the environment to interact with the framework and region server.
* @deprecated As of release 2.0.0 with out any replacement. This is maintained for internal
* usage by AccessController. Do not use these hooks in custom co-processors.
*/
@Deprecated
default void preReplicateLogEntries(final ObserverContext ctx)
throws IOException {
}
/**
* This will be called after executing replication request to shipping log entries.
* @param ctx the environment to interact with the framework and region server.
* @deprecated As of release 2.0.0 with out any replacement. This is maintained for internal
* usage by AccessController. Do not use these hooks in custom co-processors.
*/
@Deprecated
default void postReplicateLogEntries(
final ObserverContext ctx) throws IOException {
}
/**
* This will be called before clearing compaction queues
* @param ctx the environment to interact with the framework and region server.
*/
default void preClearCompactionQueues(
final ObserverContext ctx)
throws IOException {}
/**
* This will be called after clearing compaction queues
* @param ctx the environment to interact with the framework and region server.
*/
default void postClearCompactionQueues(
final ObserverContext ctx)
throws IOException {}
/**
* This will be called before executing procedures
* @param ctx the environment to interact with the framework and region server.
*/
default void preExecuteProcedures(ObserverContext ctx)
throws IOException {}
/**
* This will be called after executing procedures
* @param ctx the environment to interact with the framework and region server.
*/
default void postExecuteProcedures(ObserverContext ctx)
throws IOException {}
}