1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, software 13 * distributed under the License is distributed on an "AS IS" BASIS, 14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 * See the License for the specific language governing permissions and 16 * limitations under the License. 17 */ 18 19 package org.apache.giraph.metrics; 20 21 import org.apache.log4j.Logger; 22 23 import com.yammer.metrics.core.Metric; 24 import com.yammer.metrics.core.MetricName; 25 import com.yammer.metrics.core.MetricsRegistryListener; 26 27 /** 28 * A simple MetricsRegistry listener that prints every Metric added/removed. 29 */ 30 public class MetricsRegistryDebugger implements MetricsRegistryListener { 31 /** logger instance */ 32 private static final Logger LOG = 33 Logger.getLogger(MetricsRegistryDebugger.class); 34 /** static singleton instance */ 35 private static final MetricsRegistryDebugger INSTANCE = 36 new MetricsRegistryDebugger(); 37 38 /** 39 * Get singleton static instance of this class. 40 * 41 * @return singleton static instance. 42 */ 43 public static MetricsRegistryDebugger get() { 44 return INSTANCE; 45 } 46 47 @Override 48 public void onMetricAdded(MetricName name, Metric metric) { 49 LOG.info("Adding metric " + name + " - " + 50 metric.getClass().getSimpleName()); 51 } 52 53 @Override 54 public void onMetricRemoved(MetricName name) { 55 LOG.info("Removing metric " + name); 56 } 57 }