rakeshadr commented on code in PR #10000: URL: https://github.com/apache/ozone/pull/10000#discussion_r3044878303
########## 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(); + } + } + + public PendingContainerTracker(long maxContainerSize) { + this(maxContainerSize, 10 * 60 * 1000, null); // Default 10 minutes + } + + public PendingContainerTracker(long maxContainerSize, long rollIntervalMs, + SCMNodeMetrics metrics) { + this.datanodeBuckets = new ConcurrentHashMap<>(); + this.maxContainerSize = maxContainerSize; + this.rollIntervalMs = rollIntervalMs; + this.metrics = metrics; + LOG.info("PendingContainerTracker initialized with maxContainerSize={}B, rollInterval={}ms", + maxContainerSize, rollIntervalMs); + } + + /** + * Whether the datanode can fit another container of {@code containerSize} after accounting for + * SCM pending allocations for {@code node} (this tracker) and usable space on {@code datanodeInfo}. + * Combines {@link #getPendingAllocationSize} with the per-disk slot check in one call. + * + * @param node identity used to look up pending allocations (same DN as {@code datanodeInfo}) + * @param datanodeInfo storage reports for the datanode + * @param containerSize required container size in bytes (typically SCM max container size) + */ + /** + * Advances the two-window tumbling bucket for this datanode when the roll interval has elapsed. + * Call on periodic paths (e.g. node report) so windows age even when there are no new + * allocations or container reports touching this tracker. + */ + public void rollWindowsIfNeeded(DatanodeDetails node) { + if (node == null) { + return; + } + UUID uuid = node.getUuid(); + TwoWindowBucket bucket = datanodeBuckets.get(uuid); + if (bucket == null) { + return; + } + synchronized (bucket) { + bucket.rollIfNeeded(); + if (bucket.isEmpty()) { + datanodeBuckets.remove(uuid, bucket); + } + } + } + + public boolean hasEffectiveAllocatableSpaceForNewContainer( + DatanodeDetails node, DatanodeInfo datanodeInfo, long containerSize) { + if (node == null || datanodeInfo == null || containerSize <= 0) { + return false; + } + long pendingBytes = getPendingAllocationSize(node); + return hasAllocatableSpaceAfterPending(datanodeInfo, containerSize, pendingBytes); + } + + private static boolean hasAllocatableSpaceAfterPending( + DatanodeInfo datanodeInfo, long containerSize, long pendingAllocationBytes) { + List<StorageReportProto> storageReports = datanodeInfo.getStorageReports(); + if (storageReports == null || storageReports.isEmpty()) { + return false; + } + long effectiveAllocatableSpace = 0L; + for (StorageReportProto report : storageReports) { + long usableSpace = VolumeUsage.getUsableSpace(report); + long containersOnThisDisk = usableSpace / containerSize; + effectiveAllocatableSpace += containersOnThisDisk * containerSize; + if (effectiveAllocatableSpace - pendingAllocationBytes >= containerSize) { + return true; + } + } + return false; + } + + /** + * Drops all pending allocation state for a datanode (e.g. stale/dead cleanup). + */ + public void clearPendingForDatanode(DatanodeDetails node) { + if (node == null) { + return; + } + UUID uuid = node.getUuid(); + TwoWindowBucket bucket = datanodeBuckets.get(uuid); + if (bucket == null) { + return; + } + synchronized (bucket) { + datanodeBuckets.remove(uuid, bucket); Review Comment: Please use CHM mutation, that will simplify it. ``` if (node == null) { return; } UUID uuid = node.getUuid(); if (datanodeBuckets.remove(uuid) != null) { LOG.debug("Cleared pending container allocations for datanode {}", node.getUuidString()); } ``` _Important lock design principle:-_ PendingContainerTracker: Please ensure no bucket -> map mutation path anymore. You need to switch remove/roll/clear to concurrenthashmap compute-based mutations, keep bucket internals intact. -- 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]
