| /** |
| * 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); |
| } |
