org.elasticsearch.cluster.routing.allocation.decider.EnableAllocationDecider Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
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.cluster.routing.allocation.decider;
import org.elasticsearch.cluster.metadata.IndexMetadata;
import org.elasticsearch.cluster.routing.RecoverySource;
import org.elasticsearch.cluster.routing.RoutingNode;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
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 java.util.Locale;
/**
* This allocation decider allows shard allocations / rebalancing via the cluster wide settings
* {@link #CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING} / {@link #CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING} and the per index setting
* {@link #INDEX_ROUTING_ALLOCATION_ENABLE_SETTING} / {@link #INDEX_ROUTING_REBALANCE_ENABLE_SETTING}.
* The per index settings overrides the cluster wide setting.
*
*
* Allocation settings can have the following values (non-casesensitive):
*
* -
NONE
- no shard allocation is allowed.
* -
NEW_PRIMARIES
- only primary shards of new indices are allowed to be allocated
* -
PRIMARIES
- only primary shards are allowed to be allocated
* -
ALL
- all shards are allowed to be allocated
*
*
*
* Rebalancing settings can have the following values (non-casesensitive):
*
* -
NONE
- no shard rebalancing is allowed.
* -
REPLICAS
- only replica shards are allowed to be balanced
* -
PRIMARIES
- only primary shards are allowed to be balanced
* -
ALL
- all shards are allowed to be balanced
*
*
* @see Rebalance
* @see Allocation
*/
public class EnableAllocationDecider extends AllocationDecider {
public static final String NAME = "enable";
public static final Setting CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING = Setting.enumSetting(
Allocation.class,
"cluster.routing.allocation.enable",
Allocation.ALL,
Property.Dynamic,
Property.NodeScope
);
public static final Setting INDEX_ROUTING_ALLOCATION_ENABLE_SETTING = Setting.enumSetting(
Allocation.class,
"index.routing.allocation.enable",
Allocation.ALL,
Property.Dynamic,
Property.IndexScope
);
public static final Setting CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING = Setting.enumSetting(
Rebalance.class,
"cluster.routing.rebalance.enable",
Rebalance.ALL,
Property.Dynamic,
Property.NodeScope
);
public static final Setting INDEX_ROUTING_REBALANCE_ENABLE_SETTING = Setting.enumSetting(
Rebalance.class,
"index.routing.rebalance.enable",
Rebalance.ALL,
Property.Dynamic,
Property.IndexScope
);
private volatile Rebalance enableRebalance;
private volatile Allocation enableAllocation;
public EnableAllocationDecider(Settings settings, ClusterSettings clusterSettings) {
this.enableAllocation = CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.get(settings);
this.enableRebalance = CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.get(settings);
clusterSettings.addSettingsUpdateConsumer(CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING, this::setEnableAllocation);
clusterSettings.addSettingsUpdateConsumer(CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING, this::setEnableRebalance);
}
private void setEnableRebalance(Rebalance enableRebalance) {
this.enableRebalance = enableRebalance;
}
private void setEnableAllocation(Allocation enableAllocation) {
this.enableAllocation = enableAllocation;
}
@Override
public Decision canAllocate(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation) {
return canAllocate(shardRouting, allocation);
}
@Override
public Decision canAllocate(ShardRouting shardRouting, RoutingAllocation allocation) {
if (allocation.ignoreDisable()) {
return allocation.decision(
Decision.YES,
NAME,
"explicitly ignoring any disabling of allocation due to manual allocation commands via the reroute API"
);
}
final IndexMetadata indexMetadata = allocation.metadata().getIndexSafe(shardRouting.index());
final Allocation enable;
final boolean usedIndexSetting;
if (INDEX_ROUTING_ALLOCATION_ENABLE_SETTING.exists(indexMetadata.getSettings())) {
enable = INDEX_ROUTING_ALLOCATION_ENABLE_SETTING.get(indexMetadata.getSettings());
usedIndexSetting = true;
} else {
enable = this.enableAllocation;
usedIndexSetting = false;
}
return switch (enable) {
case ALL -> allocation.decision(Decision.YES, NAME, "all allocations are allowed");
case NONE -> allocation.decision(Decision.NO, NAME, "no allocations are allowed due to %s", setting(enable, usedIndexSetting));
case NEW_PRIMARIES -> (shardRouting.primary()
&& shardRouting.active() == false
&& shardRouting.recoverySource().getType() != RecoverySource.Type.EXISTING_STORE)
? allocation.decision(Decision.YES, NAME, "new primary allocations are allowed")
: allocation.decision(
Decision.NO,
NAME,
"non-new primary allocations are forbidden due to %s",
setting(enable, usedIndexSetting)
);
case PRIMARIES -> shardRouting.primary()
? allocation.decision(Decision.YES, NAME, "primary allocations are allowed")
: allocation.decision(Decision.NO, NAME, "replica allocations are forbidden due to %s", setting(enable, usedIndexSetting));
};
}
@Override
public Decision canRebalance(RoutingAllocation allocation) {
if (allocation.ignoreDisable()) {
return allocation.decision(Decision.YES, NAME, "allocation is explicitly ignoring any disabling of rebalancing");
}
if (enableRebalance == Rebalance.NONE) {
for (IndexMetadata indexMetadata : allocation.metadata()) {
if (INDEX_ROUTING_REBALANCE_ENABLE_SETTING.exists(indexMetadata.getSettings())
&& INDEX_ROUTING_REBALANCE_ENABLE_SETTING.get(indexMetadata.getSettings()) != Rebalance.NONE) {
return allocation.decision(Decision.YES, NAME, "rebalancing is permitted on one or more indices");
}
}
return allocation.decision(Decision.NO, NAME, "no rebalancing is allowed due to %s", setting(enableRebalance, false));
}
return allocation.decision(Decision.YES, NAME, "rebalancing is not globally disabled");
}
@Override
public Decision canRebalance(ShardRouting shardRouting, RoutingAllocation allocation) {
if (allocation.ignoreDisable()) {
return allocation.decision(Decision.YES, NAME, "allocation is explicitly ignoring any disabling of rebalancing");
}
Settings indexSettings = allocation.metadata().getIndexSafe(shardRouting.index()).getSettings();
final Rebalance enable;
final boolean usedIndexSetting;
if (INDEX_ROUTING_REBALANCE_ENABLE_SETTING.exists(indexSettings)) {
enable = INDEX_ROUTING_REBALANCE_ENABLE_SETTING.get(indexSettings);
usedIndexSetting = true;
} else {
enable = this.enableRebalance;
usedIndexSetting = false;
}
return switch (enable) {
case ALL -> allocation.decision(Decision.YES, NAME, "all rebalancing is allowed");
case NONE -> allocation.decision(Decision.NO, NAME, "no rebalancing is allowed due to %s", setting(enable, usedIndexSetting));
case PRIMARIES -> shardRouting.primary()
? allocation.decision(Decision.YES, NAME, "primary rebalancing is allowed")
: allocation.decision(Decision.NO, NAME, "replica rebalancing is forbidden due to %s", setting(enable, usedIndexSetting));
case REPLICAS -> shardRouting.primary()
? allocation.decision(Decision.NO, NAME, "primary rebalancing is forbidden due to %s", setting(enable, usedIndexSetting))
: allocation.decision(Decision.YES, NAME, "replica rebalancing is allowed");
};
}
private static String setting(Allocation allocation, boolean usedIndexSetting) {
StringBuilder buf = new StringBuilder();
if (usedIndexSetting) {
buf.append("index setting [");
buf.append(INDEX_ROUTING_ALLOCATION_ENABLE_SETTING.getKey());
} else {
buf.append("cluster setting [");
buf.append(CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING.getKey());
}
buf.append("=").append(allocation.toString().toLowerCase(Locale.ROOT)).append("]");
return buf.toString();
}
private static String setting(Rebalance rebalance, boolean usedIndexSetting) {
StringBuilder buf = new StringBuilder();
if (usedIndexSetting) {
buf.append("index setting [");
buf.append(INDEX_ROUTING_REBALANCE_ENABLE_SETTING.getKey());
} else {
buf.append("cluster setting [");
buf.append(CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING.getKey());
}
buf.append("=").append(rebalance.toString().toLowerCase(Locale.ROOT)).append("]");
return buf.toString();
}
/**
* Allocation values or rather their string representation to be used used with
* {@link EnableAllocationDecider#CLUSTER_ROUTING_ALLOCATION_ENABLE_SETTING} /
* {@link EnableAllocationDecider#INDEX_ROUTING_ALLOCATION_ENABLE_SETTING}
* via cluster / index settings.
*/
public enum Allocation {
NONE,
NEW_PRIMARIES,
PRIMARIES,
ALL;
@Override
public String toString() {
return name().toLowerCase(Locale.ROOT);
}
}
/**
* Rebalance values or rather their string representation to be used used with
* {@link EnableAllocationDecider#CLUSTER_ROUTING_REBALANCE_ENABLE_SETTING} /
* {@link EnableAllocationDecider#INDEX_ROUTING_REBALANCE_ENABLE_SETTING}
* via cluster / index settings.
*/
public enum Rebalance {
NONE,
PRIMARIES,
REPLICAS,
ALL;
@Override
public String toString() {
return name().toLowerCase(Locale.ROOT);
}
}
}