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.coprocessor;
019
020import org.apache.hadoop.hbase.CoprocessorEnvironment;
021import org.apache.hadoop.hbase.HBaseInterfaceAudience;
022import org.apache.hadoop.hbase.metrics.MetricRegistry;
023import org.apache.hadoop.hbase.wal.WAL;
024import org.apache.yetus.audience.InterfaceAudience;
025import org.apache.yetus.audience.InterfaceStability;
026
027@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
028@InterfaceStability.Evolving
029public interface WALCoprocessorEnvironment extends CoprocessorEnvironment<WALCoprocessor> {
030  /** Returns reference to the region server's WAL */
031  WAL getWAL();
032
033  /**
034   * Returns a MetricRegistry that can be used to track metrics at the region server level.
035   * <p>
036   * See ExampleRegionServerObserverWithMetrics class in the hbase-examples modules for examples of
037   * how metrics can be instantiated and used.
038   * </p>
039   * @return A MetricRegistry for the coprocessor class to track and export metrics.
040   */
041  MetricRegistry getMetricRegistryForRegionServer();
042}