Package org.elasticsearch.cluster.coordination

Class DiscoveryUpgradeService

java.lang.Object

org.elasticsearch.cluster.coordination.DiscoveryUpgradeService

public class DiscoveryUpgradeService
extends Object

Deals with rolling upgrades of the cluster coordination layer. In mixed clusters we prefer to elect the older nodes, but when the last old node shuts down then as long as there are enough new nodes we can assume that they form the whole cluster and define them as the initial configuration.

Field Summary

Fields

Modifier and Type	Field	Description
static Setting<org.elasticsearch.core.TimeValue>	BWC_PING_TIMEOUT_SETTING
static Setting<Boolean>	ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING

Constructor Summary

Constructors

Constructor	Description
DiscoveryUpgradeService(Settings settings, TransportService transportService, BooleanSupplier isBootstrappedSupplier, JoinHelper joinHelper, Supplier<Iterable<DiscoveryNode>> peersSupplier, Consumer<CoordinationMetadata.VotingConfiguration> initialConfigurationConsumer)

Method Summary

Modifier and Type	Method	Description
void	activate(Optional<DiscoveryNode> lastKnownLeader, ClusterState lastAcceptedClusterState)
static DiscoveryNode	createDiscoveryNodeWithImpossiblyHighId(DiscoveryNode node)	Pre-7.0 nodes select the best master by comparing their IDs (as strings) and selecting the lowest one amongst those nodes with the best cluster state version.
void	deactivate()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

BWC_PING_TIMEOUT_SETTING

public static final Setting<org.elasticsearch.core.TimeValue> BWC_PING_TIMEOUT_SETTING

ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING

public static final Setting<Boolean> ENABLE_UNSAFE_BOOTSTRAPPING_ON_UPGRADE_SETTING

Constructor Details

DiscoveryUpgradeService

public DiscoveryUpgradeService(Settings settings,
 TransportService transportService,
 BooleanSupplier isBootstrappedSupplier,
 JoinHelper joinHelper,
 Supplier<Iterable<DiscoveryNode>> peersSupplier,
 Consumer<CoordinationMetadata.VotingConfiguration> initialConfigurationConsumer)

Method Details

activate

public void activate(Optional<DiscoveryNode> lastKnownLeader,
 ClusterState lastAcceptedClusterState)

deactivate

public void deactivate()

createDiscoveryNodeWithImpossiblyHighId

public static DiscoveryNode createDiscoveryNodeWithImpossiblyHighId(DiscoveryNode node)

Pre-7.0 nodes select the best master by comparing their IDs (as strings) and selecting the lowest one amongst those nodes with the best cluster state version. We want 7.0+ nodes to participate in these elections in a mixed cluster but never to win one, so we lie and claim to have an impossible ID that compares above all genuine IDs.