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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.indices.breaker.CircuitBreakerService;
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,
CircuitBreakerService circuitBreakerService
) {
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,
circuitBreakerService
);
} 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;
}
}