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 /** 22 * An aggregator over metrics from multiple hosts. Computes min, max, and mean. 23 * 24 * @param <T> value type 25 */ 26 public abstract class AggregatedMetric<T extends Number> { 27 /** Minimum value seen with the host that it came from */ 28 protected ValueWithHostname<T> min; 29 /** Maximum value seen with the host that it came from */ 30 protected ValueWithHostname<T> max; 31 /** Total of all the values seen */ 32 protected T sum; 33 /** Number of values seen */ 34 protected long count; 35 36 /** 37 * Add another item to the aggregation. 38 * 39 * @param value value to add 40 * @param hostnamePartitionId String hostname it came from 41 */ 42 public abstract void addItem(T value, String hostnamePartitionId); 43 44 /** 45 * Whether this AggregatedMetric has any data. 46 * 47 * @return true if we have any data. 48 */ 49 public boolean hasData() { 50 return count > 0; 51 } 52 53 /** 54 * Get minimum value together with host it came from. 55 * 56 * @return ValueWithHostname for minimum 57 */ 58 public ValueWithHostname<T> min() { 59 return min; 60 } 61 62 /** 63 * Get maximum value together with host it came from. 64 * 65 * @return ValueWithHostname for maximum 66 */ 67 public ValueWithHostname<T> max() { 68 return max; 69 } 70 71 /** 72 * Get total of all the values seen 73 * 74 * @return total of values seen 75 */ 76 public T sum() { 77 return sum; 78 } 79 80 /** 81 * Get average of all the values 82 * 83 * @return computed average of all the values 84 */ 85 public abstract double mean(); 86 87 /** 88 * Get number of values seen 89 * 90 * @return count of values 91 */ 92 public long count() { 93 return count; 94 } 95 } 96