1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
|
/*
* 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.cluster.routing.allocation.decider;
import org.elasticsearch.cluster.routing.ShardRouting;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.common.inject.Inject;
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 {@link AllocationDecider} controls re-balancing operations based on the
* cluster wide active shard state. This decided can not be configured in
* real-time and should be pre-cluster start via
* <tt>cluster.routing.allocation.allow_rebalance</tt>. This setting respects the following
* values:
* <ul>
* <li><tt>indices_primaries_active</tt> - Re-balancing is allowed only once all
* primary shards on all indices are active.</li>
*
* <li><tt>indices_all_active</tt> - Re-balancing is allowed only once all
* shards on all indices are active.</li>
*
* <li><tt>always</tt> - Re-balancing is allowed once a shard replication group
* is active</li>
* </ul>
*/
public class ClusterRebalanceAllocationDecider extends AllocationDecider {
public static final String NAME = "cluster_rebalance";
public static final Setting<ClusterRebalanceType> CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING =
new Setting<>("cluster.routing.allocation.allow_rebalance", ClusterRebalanceType.INDICES_ALL_ACTIVE.name().toLowerCase(Locale.ROOT),
ClusterRebalanceType::parseString, Property.Dynamic, Property.NodeScope);
/**
* An enum representation for the configured re-balance type.
*/
public static enum ClusterRebalanceType {
/**
* Re-balancing is allowed once a shard replication group is active
*/
ALWAYS,
/**
* Re-balancing is allowed only once all primary shards on all indices are active.
*/
INDICES_PRIMARIES_ACTIVE,
/**
* Re-balancing is allowed only once all shards on all indices are active.
*/
INDICES_ALL_ACTIVE;
public static ClusterRebalanceType parseString(String typeString) {
if ("always".equalsIgnoreCase(typeString)) {
return ClusterRebalanceType.ALWAYS;
} else if ("indices_primaries_active".equalsIgnoreCase(typeString) || "indicesPrimariesActive".equalsIgnoreCase(typeString)) {
return ClusterRebalanceType.INDICES_PRIMARIES_ACTIVE;
} else if ("indices_all_active".equalsIgnoreCase(typeString) || "indicesAllActive".equalsIgnoreCase(typeString)) {
return ClusterRebalanceType.INDICES_ALL_ACTIVE;
}
throw new IllegalArgumentException("Illegal value for " +
CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING + ": " + typeString);
}
}
private volatile ClusterRebalanceType type;
@Inject
public ClusterRebalanceAllocationDecider(Settings settings, ClusterSettings clusterSettings) {
super(settings);
try {
type = CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING.get(settings);
} catch (IllegalStateException e) {
logger.warn("[{}] has a wrong value {}, defaulting to 'indices_all_active'",
CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING,
CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING.getRaw(settings));
type = ClusterRebalanceType.INDICES_ALL_ACTIVE;
}
logger.debug("using [{}] with [{}]", CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING.getKey(),
type.toString().toLowerCase(Locale.ROOT));
clusterSettings.addSettingsUpdateConsumer(CLUSTER_ROUTING_ALLOCATION_ALLOW_REBALANCE_SETTING, this::setType);
}
private void setType(ClusterRebalanceType type) {
this.type = type;
}
@Override
public Decision canRebalance(ShardRouting shardRouting, RoutingAllocation allocation) {
return canRebalance(allocation);
}
@Override
public Decision canRebalance(RoutingAllocation allocation) {
if (type == ClusterRebalanceType.INDICES_PRIMARIES_ACTIVE) {
// check if there are unassigned primaries.
if ( allocation.routingNodes().hasUnassignedPrimaries() ) {
return allocation.decision(Decision.NO, NAME,
"the cluster has unassigned primary shards and rebalance type is set to [%s]", type);
}
// check if there are initializing primaries that don't have a relocatingNodeId entry.
if ( allocation.routingNodes().hasInactivePrimaries() ) {
return allocation.decision(Decision.NO, NAME,
"the cluster has inactive primary shards and rebalance type is set to [%s]", type);
}
return allocation.decision(Decision.YES, NAME, "all primary shards are active");
}
if (type == ClusterRebalanceType.INDICES_ALL_ACTIVE) {
// check if there are unassigned shards.
if (allocation.routingNodes().hasUnassignedShards() ) {
return allocation.decision(Decision.NO, NAME,
"the cluster has unassigned shards and rebalance type is set to [%s]", type);
}
// in case all indices are assigned, are there initializing shards which
// are not relocating?
if ( allocation.routingNodes().hasInactiveShards() ) {
return allocation.decision(Decision.NO, NAME,
"the cluster has inactive shards and rebalance type is set to [%s]", type);
}
}
// type == Type.ALWAYS
return allocation.decision(Decision.YES, NAME, "all shards are active, rebalance type is [%s]", type);
}
}
|
