wardlican commented on code in PR #3922: URL: https://github.com/apache/amoro/pull/3922#discussion_r2923888908
########## amoro-ams/src/main/java/org/apache/amoro/server/AmsAssignService.java: ########## @@ -0,0 +1,453 @@ +/* + * 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.amoro.server; + +import org.apache.amoro.client.AmsServerInfo; +import org.apache.amoro.config.Configurations; +import org.apache.amoro.server.ha.HighAvailabilityContainer; +import org.apache.amoro.shade.guava32.com.google.common.util.concurrent.ThreadFactoryBuilder; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.util.ArrayList; +import java.util.HashSet; +import java.util.List; +import java.util.Map; +import java.util.Set; +import java.util.concurrent.Executors; +import java.util.concurrent.ScheduledExecutorService; +import java.util.concurrent.TimeUnit; + +/** + * Service for assigning bucket IDs to AMS nodes in master-slave mode. Periodically detects node + * changes and redistributes bucket IDs evenly. + */ +public class AmsAssignService { + + private static final Logger LOG = LoggerFactory.getLogger(AmsAssignService.class); + + private final ScheduledExecutorService assignScheduler = + Executors.newSingleThreadScheduledExecutor( + new ThreadFactoryBuilder() + .setNameFormat("ams-assign-scheduler-%d") + .setDaemon(true) + .build()); + + private final HighAvailabilityContainer haContainer; + private final BucketAssignStore assignStore; + private final Configurations serviceConfig; + private final int bucketIdTotalCount; + private final long nodeOfflineTimeoutMs; + private final long assignIntervalSeconds; + private volatile boolean running = false; + + boolean isRunning() { + return running; + } + + void doAssignForTest() { + doAssign(); + } + + public AmsAssignService(HighAvailabilityContainer haContainer, Configurations serviceConfig) { + this.haContainer = haContainer; + this.serviceConfig = serviceConfig; + this.bucketIdTotalCount = + serviceConfig.getInteger(AmoroManagementConf.HA_BUCKET_ID_TOTAL_COUNT); + this.nodeOfflineTimeoutMs = + serviceConfig.get(AmoroManagementConf.NODE_OFFLINE_TIMEOUT).toMillis(); + this.assignIntervalSeconds = + serviceConfig.get(AmoroManagementConf.ASSIGN_INTERVAL).getSeconds(); + this.assignStore = BucketAssignStoreFactory.create(haContainer, serviceConfig); + } + + /** + * Start the assignment service. Only works in master-slave mode and when current node is leader. + */ + public void start() { + if (!serviceConfig.getBoolean(AmoroManagementConf.USE_MASTER_SLAVE_MODE)) { + LOG.info("Master-slave mode is not enabled, skip starting bucket assignment service"); + return; + } + if (running) { + LOG.warn("Bucket assignment service is already running"); + return; + } + running = true; + assignScheduler.scheduleWithFixedDelay( + this::doAssign, 10, assignIntervalSeconds, TimeUnit.SECONDS); + LOG.info("Bucket assignment service started with interval: {} seconds", assignIntervalSeconds); + } + + /** Stop the assignment service. */ + public void stop() { + if (!running) { + return; + } + running = false; + assignScheduler.shutdown(); + try { + if (!assignScheduler.awaitTermination(5, TimeUnit.SECONDS)) { + assignScheduler.shutdownNow(); + } + } catch (InterruptedException e) { + assignScheduler.shutdownNow(); + Thread.currentThread().interrupt(); + } + LOG.info("Bucket assignment service stopped"); + } + + private void doAssign() { + try { + if (!haContainer.hasLeadership()) { + LOG.debug("Current node is not leader, skip bucket assignment"); + return; + } + + List<AmsServerInfo> aliveNodes = haContainer.getAliveNodes(); + if (aliveNodes.isEmpty()) { + LOG.debug("No alive nodes found, skip bucket assignment"); + return; + } + + Map<AmsServerInfo, List<String>> currentAssignments = assignStore.getAllAssignments(); + + // Create a mapping from stored nodes (may have null restBindPort) to alive nodes (complete + // info) + // Use host:thriftBindPort as the key for matching + Map<String, AmsServerInfo> aliveNodeMap = new java.util.HashMap<>(); + for (AmsServerInfo node : aliveNodes) { + String key = getNodeKey(node); + aliveNodeMap.put(key, node); + } + + // Normalize current assignments: map stored nodes to their corresponding alive nodes + Map<AmsServerInfo, List<String>> normalizedAssignments = new java.util.HashMap<>(); + Set<AmsServerInfo> currentAssignedNodes = new HashSet<>(); + for (Map.Entry<AmsServerInfo, List<String>> entry : currentAssignments.entrySet()) { + AmsServerInfo storedNode = entry.getKey(); + String nodeKey = getNodeKey(storedNode); + AmsServerInfo aliveNode = aliveNodeMap.get(nodeKey); + if (aliveNode != null) { + // Node is alive, use the complete node info from aliveNodes + normalizedAssignments.put(aliveNode, entry.getValue()); + currentAssignedNodes.add(aliveNode); + } else { + // Node is not in alive list, keep the stored node info for offline detection + normalizedAssignments.put(storedNode, entry.getValue()); + currentAssignedNodes.add(storedNode); + } + } + + Set<AmsServerInfo> aliveNodeSet = new HashSet<>(aliveNodes); + + // Detect new nodes and offline nodes + Set<AmsServerInfo> newNodes = new HashSet<>(aliveNodeSet); + newNodes.removeAll(currentAssignedNodes); + + Set<AmsServerInfo> offlineNodes = new HashSet<>(); + for (AmsServerInfo storedNode : currentAssignments.keySet()) { + String nodeKey = getNodeKey(storedNode); + if (!aliveNodeMap.containsKey(nodeKey)) { + offlineNodes.add(storedNode); + } + } + + // Check for nodes that haven't updated for a long time + long currentTime = System.currentTimeMillis(); + Set<String> aliveNodeKeys = new HashSet<>(); + for (AmsServerInfo node : aliveNodes) { + aliveNodeKeys.add(getNodeKey(node)); + } + for (AmsServerInfo node : currentAssignedNodes) { + String nodeKey = getNodeKey(node); + if (aliveNodeKeys.contains(nodeKey)) { + long lastUpdateTime = assignStore.getLastUpdateTime(node); + if (lastUpdateTime > 0 && (currentTime - lastUpdateTime) > nodeOfflineTimeoutMs) { + // Find the stored node for this alive node to add to offlineNodes + for (AmsServerInfo storedNode : currentAssignments.keySet()) { + if (getNodeKey(storedNode).equals(nodeKey)) { + offlineNodes.add(storedNode); + break; + } + } + LOG.warn( + "Node {} is considered offline due to timeout. Last update: {}", + node, + lastUpdateTime); + } + } + } + + boolean needReassign = !newNodes.isEmpty() || !offlineNodes.isEmpty(); + + if (needReassign) { + LOG.info( + "Detected node changes - New nodes: {}, Offline nodes: {}, Performing incremental reassignment...", + newNodes.size(), + offlineNodes.size()); + + // Step 1: Handle offline nodes - collect their buckets for redistribution + List<String> bucketsToRedistribute = new ArrayList<>(); + for (AmsServerInfo offlineNode : offlineNodes) { + try { + List<String> offlineBuckets = currentAssignments.get(offlineNode); + if (offlineBuckets != null && !offlineBuckets.isEmpty()) { + bucketsToRedistribute.addAll(offlineBuckets); + LOG.info( + "Collected {} buckets from offline node {} for redistribution", + offlineBuckets.size(), + offlineNode); + } + assignStore.removeAssignments(offlineNode); + } catch (Exception e) { + LOG.warn("Failed to remove assignments for offline node {}", offlineNode, e); + } + } + + // Step 2: Calculate target assignment for balanced distribution + List<String> allBuckets = generateBucketIds(); + int totalBuckets = allBuckets.size(); + int totalAliveNodes = aliveNodes.size(); + int targetBucketsPerNode = totalBuckets / totalAliveNodes; + int remainder = totalBuckets % totalAliveNodes; + + // Step 3: Incremental reassignment + // Keep existing assignments for nodes that are still alive + Map<AmsServerInfo, List<String>> newAssignments = new java.util.HashMap<>(); + Set<String> offlineNodeKeys = new HashSet<>(); + for (AmsServerInfo offlineNode : offlineNodes) { + offlineNodeKeys.add(getNodeKey(offlineNode)); + } + for (AmsServerInfo node : aliveNodes) { + String nodeKey = getNodeKey(node); + if (!offlineNodeKeys.contains(nodeKey)) { + // Node is alive and not offline, check if it has existing assignments + List<String> existingBuckets = normalizedAssignments.get(node); + if (existingBuckets != null && !existingBuckets.isEmpty()) { + // Keep existing buckets for alive nodes (not offline) + newAssignments.put(node, new ArrayList<>(existingBuckets)); + } else { + // New node + newAssignments.put(node, new ArrayList<>()); + } + } else { + // Node was offline, start with empty assignment + newAssignments.put(node, new ArrayList<>()); + } + } + + // Step 4: Redistribute buckets from offline nodes to alive nodes + if (!bucketsToRedistribute.isEmpty()) { + redistributeBucketsIncrementally(aliveNodes, bucketsToRedistribute, newAssignments); + } + + // Step 5: Handle new nodes - balance buckets from existing nodes + if (!newNodes.isEmpty()) { + balanceBucketsForNewNodes( + aliveNodes, newNodes, newAssignments, targetBucketsPerNode, remainder); + } + + // Step 6: Handle unassigned buckets (if any) + Set<String> allAssignedBuckets = new HashSet<>(); + for (List<String> buckets : newAssignments.values()) { + allAssignedBuckets.addAll(buckets); + } + List<String> unassignedBuckets = new ArrayList<>(); + for (String bucket : allBuckets) { + if (!allAssignedBuckets.contains(bucket)) { + unassignedBuckets.add(bucket); + } + } + if (!unassignedBuckets.isEmpty()) { + redistributeBucketsIncrementally(aliveNodes, unassignedBuckets, newAssignments); + } + + // Step 7: Save all new assignments + for (Map.Entry<AmsServerInfo, List<String>> entry : newAssignments.entrySet()) { + try { + assignStore.saveAssignments(entry.getKey(), entry.getValue()); + LOG.info( + "Assigned {} buckets to node {}: {}", + entry.getValue().size(), + entry.getKey(), + entry.getValue()); + } catch (Exception e) { + LOG.error("Failed to save assignments for node {}", entry.getKey(), e); + } + } + } else { + // Update last update time for alive nodes + for (AmsServerInfo node : aliveNodes) { + assignStore.updateLastUpdateTime(node); + } + } + } catch (Exception e) { + LOG.error("Error during bucket assignment", e); + } + } + + /** + * Redistribute buckets incrementally to alive nodes using round-robin. This minimizes bucket + * migration by only redistributing buckets from offline nodes. + * + * @param aliveNodes List of alive nodes + * @param bucketsToRedistribute Buckets to redistribute (from offline nodes) + * @param currentAssignments Current assignments map (will be modified) + */ + private void redistributeBucketsIncrementally( + List<AmsServerInfo> aliveNodes, + List<String> bucketsToRedistribute, + Map<AmsServerInfo, List<String>> currentAssignments) { + if (aliveNodes.isEmpty() || bucketsToRedistribute.isEmpty()) { + return; + } + + // Distribute buckets using round-robin to minimize migration + int nodeIndex = 0; + for (String bucketId : bucketsToRedistribute) { + AmsServerInfo node = aliveNodes.get(nodeIndex % aliveNodes.size()); + currentAssignments.get(node).add(bucketId); Review Comment: This problem will not occur. -- This is an automated message from the Apache Git Service. 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