rreddy-22 commented on code in PR #13443: URL: https://github.com/apache/kafka/pull/13443#discussion_r1164470089
########## group-coordinator/src/main/java/org/apache/kafka/coordinator/group/assignor/ServerSideStickyRangeAssignor.java: ########## @@ -0,0 +1,257 @@ +/* + * 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 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 :- + * <ul> + * <li> 1) Each consumer must get at least one partition per topic that it is subscribed to whenever the number of consumers is + * less than or equal to the number of partitions for that topic. (Range) </li> + * <li> 2) Partitions should be assigned to consumers in a way that facilitates join operations where required. (Range) </li> + * This can only be done if the topics are co-partitioned in the first place + * Co-partitioned:- + * Two streams are co-partitioned if the following conditions are met:- + * ->The keys must have the same schemas + * ->The topics involved must have the same number of partitions + * <li> 3) Consumers should retain as much as their previous assignment as possible. (Sticky) </li> + * </ul> + * </p> + * + * <p>The algorithm works mainly in 5 steps described below + * <ul> + * <li> 1) Get a map of the consumersPerTopic created using the member subscriptions.</li> + * <li> 2) Get a list of consumers (potentiallyUnfilled) that have not met the minimum required quota for assignment AND + * get a list of sticky partitions that we want to retain in the new assignment.</li> + * <li> 3) Add consumers from potentiallyUnfilled to Unfilled if they haven't met the total required quota = minQuota + (if necessary) extraPartition </li> + * <li> 4) Get a list of available partitions by calculating the difference between total partitions and assigned sticky partitions </li> Review Comment: done! -- 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