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 */
018
019package org.apache.hadoop.metrics2;
020
021import java.io.Closeable;
022
023import org.apache.hadoop.classification.InterfaceAudience;
024import org.apache.hadoop.classification.InterfaceStability;
025
026/**
027 * The metrics sink interface. <p>
028 * Implementations of this interface consume the {@link MetricsRecord} generated
029 * from {@link MetricsSource}. It registers with {@link MetricsSystem} which
030 * periodically pushes the {@link MetricsRecord} to the sink using
031 * {@link #putMetrics(MetricsRecord)} method.  If the implementing class also
032 * implements {@link Closeable}, then the MetricsSystem will close the sink when
033 * it is stopped.
034 */
035@InterfaceAudience.Public
036@InterfaceStability.Evolving
037public interface MetricsSink extends MetricsPlugin {
038  /**
039   * Put a metrics record in the sink
040   * @param record  the record to put
041   */
042  void putMetrics(MetricsRecord record);
043
044  /**
045   * Flush any buffered metrics
046   */
047  void flush();
048}