Gargi-jais11 commented on code in PR #8932: URL: https://github.com/apache/ozone/pull/8932#discussion_r2321461987
########## hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/diskbalancer/policy/DefaultVolumeChoosingPolicy.java: ########## @@ -0,0 +1,110 @@ +/* + * 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.hadoop.ozone.container.diskbalancer.policy; + +import java.util.List; +import java.util.Map; +import java.util.concurrent.locks.ReentrantLock; +import java.util.stream.Collectors; +import org.apache.commons.lang3.tuple.Pair; +import org.apache.hadoop.hdds.fs.SpaceUsageSource; +import org.apache.hadoop.ozone.container.common.utils.StorageVolumeUtil; +import org.apache.hadoop.ozone.container.common.volume.AvailableSpaceFilter; +import org.apache.hadoop.ozone.container.common.volume.HddsVolume; +import org.apache.hadoop.ozone.container.common.volume.MutableVolumeSet; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Choose a random volume for disk balancing. + * + * Source volumes use deltaMap to simulate space that will be freed (pre-deleted). + * Destination volumes use committedBytes to account for space already reserved. + * Both deltaMap and committedBytes are considered to calculate usage. + */ +public class DefaultVolumeChoosingPolicy implements DiskBalancerVolumeChoosingPolicy { + + public static final Logger LOG = LoggerFactory.getLogger( + DefaultVolumeChoosingPolicy.class); + private final ReentrantLock lock; + + public DefaultVolumeChoosingPolicy(ReentrantLock globalLock) { + lock = globalLock; + } + + @Override + public Pair<HddsVolume, HddsVolume> chooseVolume(MutableVolumeSet volumeSet, + double threshold, Map<HddsVolume, Long> deltaMap, long containerSize) { + lock.lock(); + try { + double idealUsage = volumeSet.getIdealUsage(); + + // Threshold is given as a percentage + double normalizedThreshold = threshold / 100; + List<HddsVolume> volumes = StorageVolumeUtil + .getHddsVolumesList(volumeSet.getVolumesList()) + .stream() + .filter(volume -> { + SpaceUsageSource usage = volume.getCurrentUsage(); + + return Math.abs( + ((double)((usage.getCapacity() - usage.getAvailable()) + + deltaMap.getOrDefault(volume, 0L) + volume.getCommittedBytes())) + / usage.getCapacity() - idealUsage) >= normalizedThreshold; + + }).sorted((v1, v2) -> { + SpaceUsageSource usage1 = v1.getCurrentUsage(); + SpaceUsageSource usage2 = v2.getCurrentUsage(); + + return Double.compare( + (double) ((usage2.getCapacity() - usage2.getAvailable()) + + deltaMap.getOrDefault(v2, 0L) + v2.getCommittedBytes()) / + usage2.getCapacity(), + (double) ((usage1.getCapacity() - usage1.getAvailable()) + + deltaMap.getOrDefault(v1, 0L) + v1.getCommittedBytes()) / + usage1.getCapacity()); + }).collect(Collectors.toList()); + + // Can not generate DiskBalancerTask if we have less than 2 results + if (volumes.size() <= 1) { + LOG.debug("Can not find appropriate Source volume and Dest Volume."); + return null; + } + AvailableSpaceFilter filter = new AvailableSpaceFilter(containerSize); + HddsVolume srcVolume = volumes.get(0); + HddsVolume destVolume = volumes.get(volumes.size() - 1); Review Comment: You are correct that we are moving on the basis of density but if you see below code part after sorting the disks on volumedensity it checks that if the last disk has enough space or not and if last disk with least utilisation doesn't have enough space for container than it moves on the previous disks if that can be the valid destination volume or not. So it only chooses destination volume with enough space and less density. https://github.com/Gargi-jais11/ozone/blob/6d88d45cf208a3f1800886fcbd7b5ba589d4d2bf/hadoop-hdds/container-service/src/main/java/org/apache/hadoop/ozone/container/diskbalancer/policy/DefaultVolumeChoosingPolicy.java#L96-L113 -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
