ashishkumar50 commented on code in PR #10000: URL: https://github.com/apache/ozone/pull/10000#discussion_r3050030672
########## hadoop-hdds/server-scm/src/main/java/org/apache/hadoop/hdds/scm/node/PendingContainerTracker.java: ########## @@ -0,0 +1,425 @@ +/* + * 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.hdds.scm.node; + +import com.google.common.annotations.VisibleForTesting; +import java.util.Collections; +import java.util.HashSet; +import java.util.List; +import java.util.Set; +import java.util.UUID; +import java.util.concurrent.ConcurrentHashMap; +import org.apache.hadoop.hdds.protocol.DatanodeDetails; +import org.apache.hadoop.hdds.protocol.proto.StorageContainerDatanodeProtocolProtos.StorageReportProto; +import org.apache.hadoop.hdds.scm.container.ContainerID; +import org.apache.hadoop.hdds.scm.pipeline.Pipeline; +import org.apache.hadoop.ozone.container.common.volume.VolumeUsage; +import org.apache.hadoop.util.Time; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +/** + * Tracks per-datanode pending container allocations at SCM using a Two Window Tumbling Bucket + * pattern (similar to HDFS HADOOP-3707). + * + * Two Window Tumbling Bucket for automatic aging and cleanup. + * + * How It Works: + * <li>Each DataNode has two sets: <b>currentWindow</b> and <b>previousWindow</b></li> + * <li>New allocations go into <b>currentWindow</b></li> + * <li>Every <b>ROLL_INTERVAL</b> (default 5 minutes): + * <ul> + * <li>previousWindow = currentWindow (shift)</li> + * <li>currentWindow = new empty set (reset)</li> + * <li>Old previousWindow is discarded (automatic aging)</li> + * </ul> + * </li> + * <li>When checking pending: return <b>union</b> of currentWindow + previousWindow</li> + * + * + * Example Timeline: + * <pre> + * Time | Action | CurrentWindow | PreviousWindow | Total Pending + * ------+---------------------------+---------------+----------------+-------------- + * 00:00 | Allocate Container-1 | {C1} | {} | {C1} + * 00:02 | Allocate Container-2 | {C1, C2} | {} | {C1, C2} + * 00:05 | [ROLL] Window tumbles | {} | {C1, C2} | {C1, C2} + * 00:07 | Allocate Container-3 | {C3} | {C1, C2} | {C1, C2, C3} + * 00:08 | Report confirms C1 | {C3} | {C2} | {C2, C3} + * 00:10 | [ROLL] Window tumbles | {} | {C3} | {C3} + * | (C2 aged out if not reported) + * </pre> + * + * <p>Thread-safety: all mutations and reads for a given datanode run under + * {@code synchronized (bucket)} on that datanode's {@link TwoWindowBucket}, including + * map insert/remove, so concurrent record/remove/report paths cannot interleave or orphan + * a bucket after it was dropped from the map.</p> + */ +public class PendingContainerTracker { + + private static final Logger LOG = LoggerFactory.getLogger(PendingContainerTracker.class); + + /** + * Roll interval in milliseconds. + * Configurable via hdds.scm.container.pending.allocation.roll.interval. + * Default: 5 minutes. + * Containers automatically age out after 2 × rollIntervalMs. + */ + private final long rollIntervalMs; + + /** + * Map of DataNode UUID to TwoWindowBucket. + */ + private final ConcurrentHashMap<UUID, TwoWindowBucket> datanodeBuckets; + + /** + * Maximum container size in bytes. + */ + private final long maxContainerSize; + + /** + * Metrics for tracking pending containers (same instance as {@link SCMNodeManager}'s node metrics). + */ + private final SCMNodeMetrics metrics; + + /** + * Two-window bucket for a single DataNode. + * Contains current and previous window sets, plus last roll timestamp. + */ + private static class TwoWindowBucket { + private Set<ContainerID> currentWindow = new HashSet<>(); + private Set<ContainerID> previousWindow = new HashSet<>(); + private long lastRollTime = Time.monotonicNow(); + private final long rollIntervalMs; + + TwoWindowBucket(long rollIntervalMs) { + this.rollIntervalMs = rollIntervalMs; + } + + /** + * Roll the windows: previous = current, current = empty. + * Called when current time exceeds lastRollTime + rollIntervalMs. + */ + synchronized void rollIfNeeded() { + long now = Time.monotonicNow(); + if (now - lastRollTime >= rollIntervalMs) { + // Shift: current becomes previous + previousWindow = currentWindow; + // Reset: new empty current window + currentWindow = new HashSet<>(); + lastRollTime = now; + LOG.debug("Rolled window. Previous window size: {}, Current window reset to empty", previousWindow.size()); + } + } + + /** + * Get union of both windows (all pending containers). + */ + synchronized Set<ContainerID> getAllPending() { + Set<ContainerID> all = new HashSet<>(); + all.addAll(currentWindow); + all.addAll(previousWindow); + return all; + } + + /** + * Add container to current window. + */ + synchronized boolean add(ContainerID containerID) { + return currentWindow.add(containerID); + } + + /** + * Remove container from both windows. + */ + synchronized boolean remove(ContainerID containerID) { + boolean removedFromCurrent = currentWindow.remove(containerID); + boolean removedFromPrevious = previousWindow.remove(containerID); + return removedFromCurrent || removedFromPrevious; + } + + /** + * Check if either window is non-empty. + */ + synchronized boolean isEmpty() { + return currentWindow.isEmpty() && previousWindow.isEmpty(); + } + + /** + * Count of pending containers in both windows. + */ + synchronized int getCount() { + return currentWindow.size() + previousWindow.size(); Review Comment: getAllPending is creating two new set which may be costly. Instead this looks less costly. Sumit had given comment above to avoid creating new list. If we want other way then we need to cache size value, which i think may not be needed here to store size as well. -- 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]
