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 */ 018 019 package org.apache.hadoop.metrics2; 020 021 import java.util.Collection; 022 023 import org.apache.hadoop.classification.InterfaceAudience; 024 import org.apache.hadoop.classification.InterfaceStability; 025 026 /** 027 * An immutable snapshot of metrics with a timestamp 028 */ 029 @InterfaceAudience.Public 030 @InterfaceStability.Evolving 031 public interface MetricsRecord { 032 /** 033 * Get the timestamp of the metrics 034 * @return the timestamp 035 */ 036 long timestamp(); 037 038 /** 039 * @return the record name 040 */ 041 String name(); 042 043 /** 044 * @return the description of the record 045 */ 046 String description(); 047 048 /** 049 * @return the context name of the record 050 */ 051 String context(); 052 053 /** 054 * Get the tags of the record 055 * Note: returning a collection instead of iterable as we 056 * need to use tags as keys (hence Collection#hashCode etc.) in maps 057 * @return an unmodifiable collection of tags 058 */ 059 Collection<MetricsTag> tags(); 060 061 /** 062 * Get the metrics of the record 063 * @return an immutable iterable interface for metrics 064 */ 065 Iterable<AbstractMetric> metrics(); 066 }