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* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.transport;
import org.elasticsearch.Version;
import org.elasticsearch.cluster.metadata.ClusterNameExpressionResolver;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.common.component.AbstractComponent;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Predicate;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Base class for all services and components that need up-to-date information about the registered remote clusters
*/
public abstract class RemoteClusterAware extends AbstractComponent {
/**
* A list of initial seed nodes to discover eligible nodes from the remote cluster
*/
public static final Setting.AffixSetting<List<InetSocketAddress>> REMOTE_CLUSTERS_SEEDS = Setting.affixKeySetting("search.remote.",
"seeds", (key) -> Setting.listSetting(key, Collections.emptyList(), RemoteClusterAware::parseSeedAddress,
Setting.Property.NodeScope, Setting.Property.Dynamic));
public static final char REMOTE_CLUSTER_INDEX_SEPARATOR = ':';
public static final String LOCAL_CLUSTER_GROUP_KEY = "";
protected final ClusterNameExpressionResolver clusterNameResolver;
/**
* Creates a new {@link RemoteClusterAware} instance
* @param settings the nodes level settings
*/
protected RemoteClusterAware(Settings settings) {
super(settings);
this.clusterNameResolver = new ClusterNameExpressionResolver(settings);
}
protected static Map<String, List<DiscoveryNode>> buildRemoteClustersSeeds(Settings settings) {
Stream<Setting<List<InetSocketAddress>>> allConcreteSettings = REMOTE_CLUSTERS_SEEDS.getAllConcreteSettings(settings);
return allConcreteSettings.collect(
Collectors.toMap(REMOTE_CLUSTERS_SEEDS::getNamespace, concreteSetting -> {
String clusterName = REMOTE_CLUSTERS_SEEDS.getNamespace(concreteSetting);
List<DiscoveryNode> nodes = new ArrayList<>();
for (InetSocketAddress address : concreteSetting.get(settings)) {
TransportAddress transportAddress = new TransportAddress(address);
DiscoveryNode node = new DiscoveryNode(clusterName + "#" + transportAddress.toString(),
transportAddress,
Version.CURRENT.minimumCompatibilityVersion());
nodes.add(node);
}
return nodes;
}));
}
/**
* Groups indices per cluster by splitting remote cluster-alias, index-name pairs on {@link #REMOTE_CLUSTER_INDEX_SEPARATOR}. All
* indices per cluster are collected as a list in the returned map keyed by the cluster alias. Local indices are grouped under
* {@link #LOCAL_CLUSTER_GROUP_KEY}. The returned map is mutable.
*
* @param requestIndices the indices in the search request to filter
* @param indexExists a predicate that can test if a certain index or alias exists in the local cluster
*
* @return a map of grouped remote and local indices
*/
public Map<String, List<String>> groupClusterIndices(String[] requestIndices, Predicate<String> indexExists) {
Map<String, List<String>> perClusterIndices = new HashMap<>();
Set<String> remoteClusterNames = getRemoteClusterNames();
for (String index : requestIndices) {
int i = index.indexOf(RemoteClusterService.REMOTE_CLUSTER_INDEX_SEPARATOR);
if (i >= 0) {
String remoteClusterName = index.substring(0, i);
List<String> clusters = clusterNameResolver.resolveClusterNames(remoteClusterNames, remoteClusterName);
if (clusters.isEmpty() == false) {
if (indexExists.test(index)) {
// we use : as a separator for remote clusters. might conflict if there is an index that is actually named
// remote_cluster_alias:index_name - for this case we fail the request. the user can easily change the cluster alias
// if that happens
throw new IllegalArgumentException("Can not filter indices; index " + index +
" exists but there is also a remote cluster named: " + remoteClusterName);
}
String indexName = index.substring(i + 1);
for (String clusterName : clusters) {
perClusterIndices.computeIfAbsent(clusterName, k -> new ArrayList<>()).add(indexName);
}
} else {
perClusterIndices.computeIfAbsent(RemoteClusterAware.LOCAL_CLUSTER_GROUP_KEY, k -> new ArrayList<>()).add(index);
}
} else {
perClusterIndices.computeIfAbsent(RemoteClusterAware.LOCAL_CLUSTER_GROUP_KEY, k -> new ArrayList<>()).add(index);
}
}
return perClusterIndices;
}
protected abstract Set<String> getRemoteClusterNames();
/**
* Subclasses must implement this to receive information about updated cluster aliases. If the given address list is
* empty the cluster alias is unregistered and should be removed.
*/
protected abstract void updateRemoteCluster(String clusterAlias, List<InetSocketAddress> addresses);
/**
* Registers this instance to listen to updates on the cluster settings.
*/
public void listenForUpdates(ClusterSettings clusterSettings) {
clusterSettings.addAffixUpdateConsumer(RemoteClusterAware.REMOTE_CLUSTERS_SEEDS, this::updateRemoteCluster,
(namespace, value) -> {});
}
private static InetSocketAddress parseSeedAddress(String remoteHost) {
int portSeparator = remoteHost.lastIndexOf(':'); // in case we have a IPv6 address ie. [::1]:9300
if (portSeparator == -1 || portSeparator == remoteHost.length()) {
throw new IllegalArgumentException("remote hosts need to be configured as [host:port], found [" + remoteHost + "] instead");
}
String host = remoteHost.substring(0, portSeparator);
InetAddress hostAddress;
try {
hostAddress = InetAddress.getByName(host);
} catch (UnknownHostException e) {
throw new IllegalArgumentException("unknown host [" + host + "]", e);
}
try {
int port = Integer.valueOf(remoteHost.substring(portSeparator + 1));
if (port <= 0) {
throw new IllegalArgumentException("port number must be > 0 but was: [" + port + "]");
}
return new InetSocketAddress(hostAddress, port);
} catch (NumberFormatException e) {
throw new IllegalArgumentException("port must be a number", e);
}
}
public static final String buildRemoteIndexName(String clusterAlias, String indexName) {
return clusterAlias + REMOTE_CLUSTER_INDEX_SEPARATOR + indexName;
}
}