jiajunwang commented on a change in pull request #1307: URL: https://github.com/apache/helix/pull/1307#discussion_r493048679
########## File path: helix-core/src/main/java/org/apache/helix/model/ClusterTrie.java ########## @@ -0,0 +1,155 @@ +package org.apache.helix.model; + +/* + * 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. + */ + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.HashMap; +import java.util.List; +import java.util.Map; +import java.util.stream.Collectors; + +import org.apache.helix.HelixException; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + + +/** + * This is a class that uses a trie data structure to represent cluster topology. Each node + * except the terminal node represents a certain domain in the topology, and an terminal node + * represents an instance in the cluster. + */ +public class ClusterTrie { + public static final String DELIMITER = "/"; + public static final String CONNECTOR = ":"; + + private static Logger logger = LoggerFactory.getLogger(ClusterTrie.class); + private TrieNode _rootNode; + private String[] _topologyKeys; + private String _faultZoneType; + private List<String> _invalidInstances = new ArrayList<>(); + + public ClusterTrie(final List<String> liveNodes, + final Map<String, InstanceConfig> instanceConfigMap, ClusterConfig clusterConfig) { + validateInstanceConfig(liveNodes, instanceConfigMap); + _topologyKeys = getTopologyDef(clusterConfig); + _faultZoneType = clusterConfig.getFaultZoneType(); + _invalidInstances = getInvalidInstancesFromConfig(instanceConfigMap, _topologyKeys); + instanceConfigMap.keySet().removeAll(_invalidInstances); + _rootNode = constructTrie(instanceConfigMap, _topologyKeys); + } + + public TrieNode getRootNode() { + return _rootNode; + } + + public String[] getTopologyKeys() { + return _topologyKeys; + } + + public String getFaultZoneType() { + return _faultZoneType; + } + + public List<String> getInvalidInstances() { + return _invalidInstances; + } + + private void validateInstanceConfig(final List<String> liveNodes, + final Map<String, InstanceConfig> instanceConfigMap) { + if (instanceConfigMap == null || !instanceConfigMap.keySet().containsAll(liveNodes)) { + List<String> liveNodesCopy = new ArrayList<>(); + liveNodesCopy.addAll(liveNodes); + throw new HelixException(String.format("Config for instances %s is not found!", + instanceConfigMap == null ? liveNodes + : liveNodesCopy.removeAll(instanceConfigMap.keySet()))); + } + } + + private List<String> getInvalidInstancesFromConfig(Map<String, InstanceConfig> instanceConfigMap, + final String[] topologyKeys) { + List<String> invalidInstances = new ArrayList<>(); + for (String instanceName : instanceConfigMap.keySet()) { + try { + Map<String, String> domainAsMap = instanceConfigMap.get(instanceName).getDomainAsMap(); + for (String key : topologyKeys) { + String value = domainAsMap.get(key); + if (value == null || value.length() == 0) { + logger.info(String.format("Domain %s for instance %s is not set", domainAsMap.get(key), + instanceName)); + invalidInstances.add(instanceName); + break; + } + } + } catch (IllegalArgumentException e) { + invalidInstances.add(instanceName); + } + } + return invalidInstances; + } + + // Note that we do not validate whether topology-aware is enabled or fault zone type is + // defined, as they do not block the construction of the trie + private String[] getTopologyDef(ClusterConfig clusterConfig) { + String[] topologyDef; + String topologyDefInConfig = clusterConfig.getTopology(); + if (topologyDefInConfig == null) { + throw new HelixException(String.format("The topology of cluster %s is empty!", + clusterConfig.getClusterName())); + } + // A list of all keys in cluster topology, e.g., a cluster topology defined as + // /group/zone/rack/host will return ["group", "zone", "rack", "host"]. + topologyDef = Arrays.asList(topologyDefInConfig.trim().split(DELIMITER)).stream() Review comment: The same example that I gave Xiaoyuan for the Topology.java change, "/group/ zone/ rack /host", do we accept this one? With your current logic, I think it will return "["group", " zone", " rack ", "host"]". Please mind the space in the keys. It will cause a mismatch in the later algorithm. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
