dajac commented on code in PR #13443: URL: https://github.com/apache/kafka/pull/13443#discussion_r1169959223
########## group-coordinator/src/main/java/org/apache/kafka/coordinator/group/assignor/RangeAssignor.java: ########## @@ -0,0 +1,240 @@ +/* + * 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.kafka.coordinator.group.assignor; + +import org.apache.kafka.common.Uuid; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.ArrayList; +import java.util.Collection; +import java.util.Collections; +import java.util.HashMap; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; + +import static java.lang.Math.min; + +/** + * <p>The Server Side Sticky Range Assignor inherits properties of both the range assignor and the sticky assignor. + * Properties are as follows: + * <ol> + * <li> Each member must get at least one partition for every topic that it is subscribed to. The only exception is when + * the number of subscribed members is greater than the number of partitions for that topic. (Range) </li> + * <li> Partitions should be assigned to members in a way that facilitates the join operation when required. (Range) </li> + * This can only be done if every member is subscribed to the same topics and the topics are co-partitioned. + * Two streams are co-partitioned if the following conditions are met: + * <ul> + * <li> The keys must have the same schemas. + * <li> The topics involved must have the same number of partitions. + * </ul> + * <li> Members should retain as much as their previous assignment as possible to reduce the number of partition movements during reassignment. (Sticky) </li> + * </ol> + * </p> + * + * <p>The algorithm includes the following steps: Review Comment: Should this section go to the javadoc of `assign`? That would be closer to the implementation. -- 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. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
