ritegarg commented on code in PR #2075: URL: https://github.com/apache/phoenix/pull/2075#discussion_r2003593158
########## phoenix-core-client/src/main/java/org/apache/phoenix/jdbc/PhoenixHACache.java: ########## @@ -0,0 +1,158 @@ +/* + * 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.phoenix.jdbc; + + +import org.apache.curator.framework.recipes.cache.ChildData; +import org.apache.curator.framework.recipes.cache.PathChildrenCache; +import org.apache.curator.framework.recipes.cache.PathChildrenCacheEvent; +import org.apache.curator.utils.ZKPaths; +import org.apache.hadoop.conf.Configuration; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import java.io.Closeable; +import java.io.IOException; +import java.util.Objects; +import java.util.List; +import java.util.Set; +import java.util.concurrent.ConcurrentHashMap; +import java.util.concurrent.CountDownLatch; +import java.util.concurrent.TimeUnit; +import java.util.stream.Collectors; + +/** + * Write-through cache for PhoenixHA. + * Uses {@link PathChildrenCache} from {@link org.apache.curator.framework.CuratorFramework}. + */ +public class PhoenixHACache implements Closeable { + + private static final long HA_CACHE_INITIALIZATION_TIMEOUT_MS = 1000L; + private static PhoenixHACache cacheInstance; + private final PhoenixHAAdmin phoenixHaAdmin; + private static final Logger LOGGER = LoggerFactory.getLogger(PhoenixHACache.class); + private final Set<String> activeToStandbyHAGroups = ConcurrentHashMap.newKeySet(); + private final PathChildrenCache pathChildrenCache; + + /** + * Creates/gets an instance of PhoenixHACache. + * + * @param conf configuration + * @return cache + */ + public static PhoenixHACache getInstance(Configuration conf) throws Exception { + PhoenixHACache result = cacheInstance; + if (result == null) { + synchronized (PhoenixHACache.class) { + result = cacheInstance; + if (result == null) { + cacheInstance = result = new PhoenixHACache(conf); + } + } + } + return result; + } + + private PhoenixHACache(final Configuration conf) throws Exception { + this.phoenixHaAdmin = new PhoenixHAAdmin(conf); + final PathChildrenCache pathChildrenCache = new PathChildrenCache(phoenixHaAdmin.getCurator(), ZKPaths.PATH_SEPARATOR, true); + final CountDownLatch latch = new CountDownLatch(1); + pathChildrenCache.getListenable().addListener((client, event) -> { + LOGGER.info("PhoenixHACache PathChildrenCache Received event for type {}", event.getType()); + final ChildData childData = event.getData(); + if (childData != null) { + if (event.getType() == PathChildrenCacheEvent.Type.CHILD_REMOVED) { + final ClusterRoleRecord crr = extractCRROrNull(childData); + if (crr != null && crr.getHaGroupName() != null && !crr.getHaGroupName().isEmpty()) { + activeToStandbyHAGroups.remove(crr.getHaGroupName()); + } + } else if (event.getType() == PathChildrenCacheEvent.Type.CHILD_ADDED + || event.getType() == PathChildrenCacheEvent.Type.CHILD_UPDATED) { + final ClusterRoleRecord crr = extractCRROrNull(childData); + if (crr != null && crr.getHaGroupName() != null) { + if (crr.getRole(phoenixHaAdmin.getZkUrl()) == ClusterRoleRecord.ClusterRole.ACTIVE_TO_STANDBY) { + activeToStandbyHAGroups.add(crr.getHaGroupName()); + } else { + activeToStandbyHAGroups.remove(crr.getHaGroupName()); + } + } + } else if (event.getType() == PathChildrenCacheEvent.Type.INITIALIZED) { + latch.countDown(); + } + } else { + LOGGER.info("PhoenixHACache PathChildrenCache Received event for type {} but ChildData is null", event.getType()); + } + }); + pathChildrenCache.start(); + this.pathChildrenCache = pathChildrenCache; + latch.await(HA_CACHE_INITIALIZATION_TIMEOUT_MS, TimeUnit.MILLISECONDS); + buildActiveToStandbySet(); + } + + private ClusterRoleRecord extractCRROrNull(final ChildData childData) { + if (childData != null) { + byte[] data = childData.getData(); + return ClusterRoleRecord.fromJson(data).orElse(null); + } + return null; + } + + private void buildActiveToStandbySet() { + List<ClusterRoleRecord> clusterRoleRecords = pathChildrenCache.getCurrentData().stream().map(this::extractCRROrNull) + .filter(Objects::nonNull).collect(Collectors.toList()); + List<String> haGroupNames = clusterRoleRecords.stream().map(ClusterRoleRecord::getHaGroupName).collect(Collectors.toList()); + for (ClusterRoleRecord crr : clusterRoleRecords) { + ClusterRoleRecord.ClusterRole role = crr.getRole(phoenixHaAdmin.getZkUrl()); + if (role == ClusterRoleRecord.ClusterRole.ACTIVE_TO_STANDBY) { + activeToStandbyHAGroups.add(crr.getHaGroupName()); + } else { + activeToStandbyHAGroups.remove(crr.getHaGroupName()); + } + } + // In case a CRR is deleted and event is not received, + // we can remove it from activeToStandbyHAGroups set now + activeToStandbyHAGroups.retainAll(haGroupNames); + } + + public void rebuild() throws Exception { + LOGGER.info("Rebuilding PhoenixHACache for HA groups"); + // NOTE: this is a BLOCKING method. + // Completely rebuild the internal cache by querying for all needed data + // WITHOUT generating any events to send to listeners. + pathChildrenCache.rebuild(); + buildActiveToStandbySet(); + LOGGER.info("Rebuild Complete for PhoenixHACache"); + } + + + @Override + public void close() throws IOException { + LOGGER.info("Closing PhoenixHACache"); + activeToStandbyHAGroups.clear(); + pathChildrenCache.close(); Review Comment: Handled exception -- 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: issues-unsubscr...@phoenix.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
