Jackie-Jiang commented on a change in pull request #4323: [Controller Separation] Add logic for lead controller resource URL: https://github.com/apache/incubator-pinot/pull/4323#discussion_r311695140
########## File path: pinot-common/src/main/java/org/apache/pinot/common/utils/helix/LeadControllerUtils.java ########## @@ -0,0 +1,111 @@ +/** + * 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.pinot.common.utils.helix; + +import java.util.Map; +import java.util.Set; +import org.apache.helix.model.ExternalView; +import org.apache.helix.model.MasterSlaveSMD; +import org.apache.pinot.common.utils.HashUtil; +import org.apache.pinot.common.utils.StringUtil; + + +public class LeadControllerUtils { + public static final String RESOURCE_ENABLED = "RESOURCE_ENABLED"; + + /** + * Gets hash code for table using murmur2 function, ignores the most significant bit. + * Note: This method CANNOT be changed when lead controller resource is enabled. + * Otherwise it will assign different controller for the same table, which will mess up the controller periodic tasks and realtime segment completion. + * @param rawTableName table name + * @return hash code ignoring the most significant bit. + */ + private static int getHashCodeForTable(String rawTableName) { + return (HashUtil.murmur2(StringUtil.encodeUtf8(rawTableName)) & Integer.MAX_VALUE); + } + + /** + * Given a raw table name and number of partitions, returns the partition id in lead controller resource. + * @param rawTableName raw table name + * @param numPartitions number of partitions + * @return partition id in lead controller resource. + */ + public static int getPartitionIdForTable(String rawTableName, int numPartitions) { + return getHashCodeForTable(rawTableName) % numPartitions; + } + + /** + * Gets lead controller participant id for table from lead controller resource. + * If the resource is disabled or no controller registered as participant, there is no instance in "MASTER" state. + * @param leadControllerResourceExternalView external view of lead controller resource + * @param rawTableName table name without type + * @return controller participant id for partition leader, e.g. Controller_localhost_9000. Null if not found or resource is disabled. + */ + public static String getLeadControllerInstanceForTable(ExternalView leadControllerResourceExternalView, + String rawTableName) { + if (leadControllerResourceExternalView == null) { + return null; + } + Set<String> partitionSet = leadControllerResourceExternalView.getPartitionSet(); + if (partitionSet == null || partitionSet.isEmpty()) { + return null; + } + int numPartitions = partitionSet.size(); + int partitionIndex = getPartitionIdForTable(rawTableName, numPartitions); + String partitionName = generatePartitionName(partitionIndex); + Map<String, String> partitionStateMap = leadControllerResourceExternalView.getStateMap(partitionName); + + // Get master host from partition map. Return null if no master found. + for (Map.Entry<String, String> entry : partitionStateMap.entrySet()) { + if (MasterSlaveSMD.States.MASTER.name().equals(entry.getValue())) { + return entry.getKey(); + } + } + return null; + } + + /** + * Generates controller participant id, e.g. returns Controller_localhost_9000 given localhost as hostname and 9000 as port. + */ + public static String generateControllerParticipantId(String controllerHost, String controllerPort) { + return org.apache.pinot.common.utils.CommonConstants.Helix.PREFIX_OF_CONTROLLER_INSTANCE + controllerHost + "_" + + controllerPort; + } + + /** + * Extracts lead controller hostname and port from controller participant id, e.g. returns localhost_9000 given Controller_localhost_9000 as controller participant id. + */ + public static String extractLeadControllerHostNameAndPort(String controllerParticipantId) { + return controllerParticipantId.substring(controllerParticipantId.indexOf("_") + 1); + } + + /** + * Generates partition name, e.g. returns leadControllerResource_0 given 0 as partition index. + */ + public static String generatePartitionName(int partitionIndex) { + return org.apache.pinot.common.utils.CommonConstants.Helix.LEAD_CONTROLLER_RESOURCE_NAME + "_" + partitionIndex; + } + + /** + * Extracts partition index from partition name, e.g. returns 0 given leadControllerResource_0 as partition name. + */ + public static int extractPartitionIndex(String partitionName) { Review comment: extractPartitionId()? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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