org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment Maven / Gradle / Ivy
/*
*
* 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.util.concurrent.ConcurrentMap;
import org.apache.hadoop.hbase.CoprocessorEnvironment;
import org.apache.hadoop.hbase.HBaseInterfaceAudience;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.hbase.classification.InterfaceStability;
import org.apache.hadoop.hbase.metrics.MetricRegistry;
import org.apache.hadoop.hbase.regionserver.Region;
import org.apache.hadoop.hbase.regionserver.RegionServerServices;
@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
@InterfaceStability.Evolving
public interface RegionCoprocessorEnvironment extends CoprocessorEnvironment {
/** @return the region associated with this coprocessor */
Region getRegion();
/** @return region information for the region this coprocessor is running on */
HRegionInfo getRegionInfo();
/** @return reference to the region server services */
RegionServerServices getRegionServerServices();
/** @return shared data between all instances of this coprocessor */
ConcurrentMap getSharedData();
/**
* Returns a MetricRegistry that can be used to track metrics at the region server level. All
* metrics tracked at this level will be shared by all the coprocessor instances
* of the same class in the same region server process. Note that there will be one
* region coprocessor environment per region in the server, but all of these instances will share
* the same MetricRegistry. The metric instances (like Counter, Timer, etc) will also be shared
* among all of the region coprocessor instances.
*
* See ExampleRegionObserverWithMetrics class in the hbase-examples modules to see examples of how
* metrics can be instantiated and used.
* @return A MetricRegistry for the coprocessor class to track and export metrics.
*/
// Note: we are not exposing getMetricRegistryForRegion(). per-region metrics are already costly
// so we do not want to allow coprocessors to export metrics at the region level. We can allow
// getMetricRegistryForTable() to allow coprocessors to track metrics per-table, per-regionserver.
MetricRegistry getMetricRegistryForRegionServer();
}