dlogothetis commented on a change in pull request #110: Counter Mechanism URL: https://github.com/apache/giraph/pull/110#discussion_r343957870
########## File path: giraph-core/src/main/java/org/apache/giraph/counters/CustomCounters.java ########## @@ -0,0 +1,128 @@ +/* + * 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.giraph.counters; + +import java.util.ArrayList; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; + +/** + * Custom counters created by the client or app + * Stores the names of the counters, and the final aggregated values + * Since there is no way to get the list of available counters from the context, + * we need to call addCustomCounter to store the information about the list of + * available counters. This is accessed by the worker/master to fetch the + * final counter values based on the group and counter name. + * It is assumed that whenever a counter is created, addCustomCounter is called, + * to enable aggregations on that counter, using the Giraph mechanism for + * aggregating counters. + */ +public class CustomCounters { + + + + /** Unique counter groups and names populated during execution of the job + * Since multiple threads can access this variable to perform read/write + * operations, we use a ConcurrentHashMap.newKeySet() to + * establish synchronisation */ + private static Set<CustomCounter> COUNTER_NAMES = + ConcurrentHashMap.newKeySet(); + + /** Aggregated counter values updated by master */ + private final List<CustomCounter> counterList; + + /** + * Create custom counters + */ + public CustomCounters() { + counterList = new ArrayList<>(); + } + + /** + * Add a counter group and name to the custom counters + * If it already exists, then it will not be added + * This will be called from the application to add the app-specific counters + * + * @param groupName Counter group + * @param counterName Counter name + * @param aggregation Type of aggregation for the counter + */ + public static void addCustomCounter(String groupName, String counterName, + CustomCounter.Aggregation aggregation) { + CustomCounter counter = new CustomCounter( + groupName, counterName, aggregation); + COUNTER_NAMES.add(counter); + } + + /** + * Get the unique counter group and names + * + * @return Map of unique counter names + */ + public static Set<CustomCounter> getCustomCounters() { + // Create a new HashSet and return that to avoid + // ConcurrentModificationException Review comment: This is not relevant any more. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
