[ https://issues.apache.org/jira/browse/HELIX-674?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16397847#comment-16397847 ]
ASF GitHub Bot commented on HELIX-674: -------------------------------------- Github user mcvsubbu commented on a diff in the pull request: https://github.com/apache/helix/pull/145#discussion_r174316247 --- Diff: helix-core/src/main/java/org/apache/helix/util/WeightAwareRebalanceUtil.java --- @@ -0,0 +1,141 @@ +package org.apache.helix.util; + +import org.apache.helix.HelixException; +import org.apache.helix.ZNRecord; +import org.apache.helix.api.config.RebalanceConfig; +import org.apache.helix.api.rebalancer.constraint.AbstractRebalanceHardConstraint; +import org.apache.helix.api.rebalancer.constraint.AbstractRebalanceSoftConstraint; +import org.apache.helix.controller.common.PartitionStateMap; +import org.apache.helix.controller.common.ResourcesStateMap; +import org.apache.helix.controller.rebalancer.strategy.ConstraintRebalanceStrategy; +import org.apache.helix.controller.stages.ClusterDataCache; +import org.apache.helix.model.*; + +import java.util.ArrayList; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * A rebalance tool that generate an resource partition assignment based on the input. + * Note the assignment won't be automatically applied to the cluster. Applications are supposed to + * apply the change. + */ --- End diff -- Good to have extensive javadoc on how to use this tool. Perhaps you intend users to see the tests, in which case you can point to a test on how to use it. One example with zk and one without will be ideal. Thanks. > Constraint Based Resource Rebalancer > ------------------------------------ > > Key: HELIX-674 > URL: https://issues.apache.org/jira/browse/HELIX-674 > Project: Apache Helix > Issue Type: New Feature > Reporter: Jiajun Wang > Assignee: Jiajun Wang > Priority: Major > Fix For: 0.8.x > > Attachments: Constraint-BasedResourceRebalancing-080318-2226-240.pdf > > > Helix rebalancer assigns resources according to different strategies. > Recently, we optimize the strategy for evenness and minimize movement. > However, the evenness here only applies to partition numbers. Moreover, we've > got more requests for customizable rebalancer from our users. > Take partition weight as an example: > In reality, partition replicas have different size. We use "partition weight" > as an abstraction of the partition size. It can be network traffic usage, > disk usage, or any other combined factors. > Given each partition may have different weights, Helix should be able to > assign partition accordingly. So that the distribution would be even > regarding the weight. > In this project, we are planning new rebalancer mechanism that generates > resource partition assignment according to a list of "constraints". Current > rebalance strategy can be regarded as one kind of constraint. Moving forward, > Helix users would be able to extend the constraint interface using their own > logic. > Some init discussions are in progress and we will have a proposal posted here > soon. -- This message was sent by Atlassian JIRA (v7.6.3#76005)