Github user ottobackwards commented on a diff in the pull request: https://github.com/apache/metron/pull/1039#discussion_r192225526 --- Diff: metron-platform/metron-storm-kafka-override/src/main/java/org/apache/storm/kafka/spout/KafkaSpoutRetryExponentialBackoff.java --- @@ -0,0 +1,328 @@ +/* + * 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.storm.kafka.spout; + +import org.apache.kafka.common.TopicPartition; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.Serializable; +import java.util.Collection; +import java.util.Comparator; +import java.util.HashMap; +import java.util.HashSet; +import java.util.Iterator; +import java.util.Map; +import java.util.Set; +import java.util.TreeSet; +import java.util.concurrent.TimeUnit; +import org.apache.commons.lang.Validate; +import org.apache.kafka.clients.consumer.ConsumerRecord; + +/** + * Implementation of {@link KafkaSpoutRetryService} using the exponential backoff formula. The time of the nextRetry is set as follows: + * nextRetry = failCount == 1 ? currentTime + initialDelay : currentTime + delayPeriod*2^(failCount-1) where failCount = 1, 2, 3, ... + * nextRetry = Min(nextRetry, currentTime + maxDelay) + */ +public class KafkaSpoutRetryExponentialBackoff implements KafkaSpoutRetryService { --- End diff -- There should also be something in the NOTICE file
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