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Elasticsearch subproject :server
/*
* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
* or more contributor license agreements. Licensed under the Elastic License
* 2.0 and the Server Side Public License, v 1; you may not use this file except
* in compliance with, at your election, the Elastic License 2.0 or the Server
* Side Public License, v 1.
*/
package org.elasticsearch.discovery;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.elasticsearch.Version;
import org.elasticsearch.client.internal.Client;
import org.elasticsearch.cluster.ClusterState;
import org.elasticsearch.cluster.coordination.Coordinator;
import org.elasticsearch.cluster.coordination.ElectionStrategy;
import org.elasticsearch.cluster.node.DiscoveryNode;
import org.elasticsearch.cluster.routing.RerouteService;
import org.elasticsearch.cluster.routing.allocation.AllocationService;
import org.elasticsearch.cluster.service.ClusterApplier;
import org.elasticsearch.cluster.service.MasterService;
import org.elasticsearch.common.Randomness;
import org.elasticsearch.common.io.stream.NamedWriteableRegistry;
import org.elasticsearch.common.logging.DeprecationCategory;
import org.elasticsearch.common.logging.DeprecationLogger;
import org.elasticsearch.common.network.NetworkService;
import org.elasticsearch.common.settings.ClusterSettings;
import org.elasticsearch.common.settings.Setting;
import org.elasticsearch.common.settings.Setting.Property;
import org.elasticsearch.common.settings.Settings;
import org.elasticsearch.common.transport.TransportAddress;
import org.elasticsearch.gateway.GatewayMetaState;
import org.elasticsearch.monitor.NodeHealthService;
import org.elasticsearch.plugins.DiscoveryPlugin;
import org.elasticsearch.transport.TransportService;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Function;
import java.util.function.Supplier;
import static org.elasticsearch.node.Node.NODE_NAME_SETTING;
/**
* A module for loading classes for node discovery.
*/
public class DiscoveryModule {
private static final Logger logger = LogManager.getLogger(DiscoveryModule.class);
public static final String MULTI_NODE_DISCOVERY_TYPE = "multi-node";
public static final String SINGLE_NODE_DISCOVERY_TYPE = "single-node";
@Deprecated
public static final String LEGACY_MULTI_NODE_DISCOVERY_TYPE = "zen";
public static final Setting DISCOVERY_TYPE_SETTING = new Setting<>(
"discovery.type",
MULTI_NODE_DISCOVERY_TYPE,
Function.identity(),
Property.NodeScope
);
public static final Setting> DISCOVERY_SEED_PROVIDERS_SETTING = Setting.listSetting(
"discovery.seed_providers",
Collections.emptyList(),
Function.identity(),
Property.NodeScope
);
public static final String DEFAULT_ELECTION_STRATEGY = "default";
public static final Setting ELECTION_STRATEGY_SETTING = new Setting<>(
"cluster.election.strategy",
DEFAULT_ELECTION_STRATEGY,
Function.identity(),
Property.NodeScope
);
private final Coordinator coordinator;
public DiscoveryModule(
Settings settings,
TransportService transportService,
Client client,
NamedWriteableRegistry namedWriteableRegistry,
NetworkService networkService,
MasterService masterService,
ClusterApplier clusterApplier,
ClusterSettings clusterSettings,
List plugins,
AllocationService allocationService,
Path configFile,
GatewayMetaState gatewayMetaState,
RerouteService rerouteService,
NodeHealthService nodeHealthService
) {
final Collection> joinValidators = new ArrayList<>();
final Map> hostProviders = new HashMap<>();
hostProviders.put("settings", () -> new SettingsBasedSeedHostsProvider(settings, transportService));
hostProviders.put("file", () -> new FileBasedSeedHostsProvider(configFile));
final Map electionStrategies = new HashMap<>();
electionStrategies.put(DEFAULT_ELECTION_STRATEGY, ElectionStrategy.DEFAULT_INSTANCE);
for (DiscoveryPlugin plugin : plugins) {
plugin.getSeedHostProviders(transportService, networkService).forEach((key, value) -> {
if (hostProviders.put(key, value) != null) {
throw new IllegalArgumentException("Cannot register seed provider [" + key + "] twice");
}
});
BiConsumer joinValidator = plugin.getJoinValidator();
if (joinValidator != null) {
joinValidators.add(joinValidator);
}
plugin.getElectionStrategies().forEach((key, value) -> {
if (electionStrategies.put(key, value) != null) {
throw new IllegalArgumentException("Cannot register election strategy [" + key + "] twice");
}
});
}
List seedProviderNames = DISCOVERY_SEED_PROVIDERS_SETTING.get(settings);
// for bwc purposes, add settings provider even if not explicitly specified
if (seedProviderNames.contains("settings") == false) {
List extendedSeedProviderNames = new ArrayList<>();
extendedSeedProviderNames.add("settings");
extendedSeedProviderNames.addAll(seedProviderNames);
seedProviderNames = extendedSeedProviderNames;
}
final Set missingProviderNames = new HashSet<>(seedProviderNames);
missingProviderNames.removeAll(hostProviders.keySet());
if (missingProviderNames.isEmpty() == false) {
throw new IllegalArgumentException("Unknown seed providers " + missingProviderNames);
}
List filteredSeedProviders = seedProviderNames.stream().map(hostProviders::get).map(Supplier::get).toList();
String discoveryType = DISCOVERY_TYPE_SETTING.get(settings);
final SeedHostsProvider seedHostsProvider = hostsResolver -> {
final List addresses = new ArrayList<>();
for (SeedHostsProvider provider : filteredSeedProviders) {
addresses.addAll(provider.getSeedAddresses(hostsResolver));
}
return Collections.unmodifiableList(addresses);
};
final ElectionStrategy electionStrategy = electionStrategies.get(ELECTION_STRATEGY_SETTING.get(settings));
if (electionStrategy == null) {
throw new IllegalArgumentException("Unknown election strategy " + ELECTION_STRATEGY_SETTING.get(settings));
}
if (LEGACY_MULTI_NODE_DISCOVERY_TYPE.equals(discoveryType)) {
assert Version.CURRENT.major == Version.V_7_0_0.major + 1;
DeprecationLogger.getLogger(DiscoveryModule.class)
.critical(
DeprecationCategory.SETTINGS,
"legacy-discovery-type",
"Support for setting [{}] to [{}] is deprecated and will be removed in a future version. Set this setting to [{}] "
+ "instead.",
DISCOVERY_TYPE_SETTING.getKey(),
LEGACY_MULTI_NODE_DISCOVERY_TYPE,
MULTI_NODE_DISCOVERY_TYPE
);
}
if (MULTI_NODE_DISCOVERY_TYPE.equals(discoveryType)
|| LEGACY_MULTI_NODE_DISCOVERY_TYPE.equals(discoveryType)
|| SINGLE_NODE_DISCOVERY_TYPE.equals(discoveryType)) {
coordinator = new Coordinator(
NODE_NAME_SETTING.get(settings),
settings,
clusterSettings,
transportService,
client,
namedWriteableRegistry,
allocationService,
masterService,
gatewayMetaState::getPersistedState,
seedHostsProvider,
clusterApplier,
joinValidators,
new Random(Randomness.get().nextLong()),
rerouteService,
electionStrategy,
nodeHealthService
);
} else {
throw new IllegalArgumentException("Unknown discovery type [" + discoveryType + "]");
}
logger.info("using discovery type [{}] and seed hosts providers {}", discoveryType, seedProviderNames);
}
public static boolean isSingleNodeDiscovery(Settings settings) {
return SINGLE_NODE_DISCOVERY_TYPE.equals(DISCOVERY_TYPE_SETTING.get(settings));
}
public Coordinator getCoordinator() {
return coordinator;
}
}