Java tutorial
/** * 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.metrics2; import org.apache.hadoop.classification.InterfaceAudience; import org.apache.hadoop.classification.InterfaceStability; /** * The source of metrics information. It generates and updates metrics. It * registers with {@link MetricsSystem}, which periodically polls it to collect * {@link MetricsRecord} and passes it to {@link MetricsSink}. */ @InterfaceAudience.Public @InterfaceStability.Evolving public interface MetricsSource { /** * Get metrics from the metrics source * @param collector to contain the resulting metrics snapshot * @param all if true, return all metrics even if unchanged. */ void getMetrics(MetricsCollector collector, boolean all); }