frankmu commented on code in PR #2846: URL: https://github.com/apache/helix/pull/2846#discussion_r1689019136
########## helix-core/src/main/java/org/apache/helix/controller/rebalancer/ConditionBasedRebalancer.java: ########## @@ -0,0 +1,179 @@ +package org.apache.helix.controller.rebalancer; + +/* + * 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. + */ + +import java.util.ArrayList; +import java.util.Collections; +import java.util.HashSet; +import java.util.LinkedHashMap; +import java.util.List; +import java.util.Map; +import java.util.Set; + +import org.apache.helix.HelixException; +import org.apache.helix.controller.dataproviders.ResourceControllerDataProvider; +import org.apache.helix.controller.rebalancer.condition.RebalanceCondition; +import org.apache.helix.controller.stages.CurrentStateOutput; +import org.apache.helix.model.IdealState; +import org.apache.helix.model.LiveInstance; +import org.apache.helix.model.Partition; +import org.apache.helix.model.Resource; +import org.apache.helix.model.ResourceAssignment; +import org.apache.helix.model.StateModelDefinition; +import org.apache.helix.zookeeper.datamodel.ZNRecord; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +public class ConditionBasedRebalancer extends AbstractRebalancer<ResourceControllerDataProvider> { + private static final Logger LOG = LoggerFactory.getLogger(ConditionBasedRebalancer.class); + private final RebalanceCondition _rebalanceCondition; + + public ConditionBasedRebalancer(RebalanceCondition rebalanceCondition) { Review Comment: I guess this is already generic where we can specify simple or complex conditions. If you check the PR description, we can do the following: Sample code to trigger the rebalance with condition `if (event type is CurrentStateChange OR CurrentStateChange)` ``` RebalanceCondition condition = new RebalanceConditionBuilder() .addCondition(() -> event.getEventType().equals(ClusterEventType.ClusterConfigChange)) .addCondition(() -> event.getEventType().equals(ClusterEventType.CurrentStateChange)) .buildOr(); Rebalancer rebalancer = new ConditionBasedRebalancer(condition); ``` We can also do nested condition as following: ``` BooleanSupplier condition1 = () -> 5 > 3; BooleanSupplier condition2 = () -> 2 > 3; BooleanSupplier condition3 = () -> event.getEventType().equals(ClusterEventType.ClusterConfigChange); BooleanSupplier condition4 = () -> event.getEventType().equals(ClusterEventType.CurrentStateChange); RebalanceCondition andCondition = new RebalanceConditionBuilder() .addCondition(condition1) .addCondition(condition3) .buildAnd(); RebalanceCondition orCondition = new RebalanceConditionBuilder() .addCondition(condition2) .addCondition(condition4) .buildOr(); RebalanceCondition nestedCondition = new RebalanceConditionBuilder() .addAndCondition(andCondition, orCondition) .buildAnd(); Rebalancer rebalancer = new ConditionBasedRebalancer(nestedCondition); ``` Let me know how do you think, open to any suggestions -- 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: reviews-unsubscr...@helix.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: reviews-unsubscr...@helix.apache.org For additional commands, e-mail: reviews-h...@helix.apache.org
