Package org.elasticsearch.cluster.routing.allocation.decider

Class AllocationDecider

java.lang.Object

org.elasticsearch.cluster.routing.allocation.decider.AllocationDecider

Direct Known Subclasses:

AllocationDeciders, AwarenessAllocationDecider, ClusterRebalanceAllocationDecider, ConcurrentRebalanceAllocationDecider, DiskThresholdDecider, EnableAllocationDecider, FilterAllocationDecider, MaxRetryAllocationDecider, NodeShutdownAllocationDecider, NodeVersionAllocationDecider, RebalanceOnlyWhenActiveAllocationDecider, ReplicaAfterPrimaryActiveAllocationDecider, ResizeAllocationDecider, RestoreInProgressAllocationDecider, SameShardAllocationDecider, ShardsLimitAllocationDecider, SnapshotInProgressAllocationDecider, ThrottlingAllocationDecider

public abstract class AllocationDecider
extends Object

AllocationDecider is an abstract base class that allows to make dynamic cluster- or index-wide shard allocation decisions on a per-node basis.

Constructor Summary

Constructors

Constructor	Description
AllocationDecider()

Method Summary

Modifier and Type	Method	Description
Decision	canAllocate(IndexMetadata indexMetadata, RoutingNode node, RoutingAllocation allocation)	Returns a Decision whether the given shard routing can be allocated at all at this state of the RoutingAllocation.
Decision	canAllocate(ShardRouting shardRouting, RoutingAllocation allocation)	Returns a Decision whether the given shard routing can be allocated at all at this state of the RoutingAllocation.
Decision	canAllocate(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation)	Returns a Decision whether the given shard routing can be allocated on the given node.
Decision	canForceAllocatePrimary(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation)	Returns a Decision whether the given primary shard can be forcibly allocated on the given node.
Decision	canRebalance(RoutingAllocation allocation)	Returns a Decision whether the cluster can execute re-balanced operations at all.
Decision	canRebalance(ShardRouting shardRouting, RoutingAllocation allocation)	Returns a Decision whether the given shard routing can be re-balanced to the given allocation.
Decision	canRemain(ShardRouting shardRouting, RoutingNode node, RoutingAllocation allocation)	Returns a Decision whether the given shard routing can be remain on the given node.
Decision	shouldAutoExpandToNode(IndexMetadata indexMetadata, DiscoveryNode node, RoutingAllocation allocation)	Returns a Decision whether shards of the given index should be auto-expanded to this node at this state of the RoutingAllocation.

Methods inherited from class java.lang.Object

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

Constructor Details

AllocationDecider

public AllocationDecider()

Method Details

canRebalance

public Decision canRebalance(ShardRouting shardRouting,
 RoutingAllocation allocation)

Returns a Decision whether the given shard routing can be re-balanced to the given allocation. The default is Decision.ALWAYS.

canAllocate

public Decision canAllocate(ShardRouting shardRouting,
 RoutingNode node,
 RoutingAllocation allocation)

Returns a Decision whether the given shard routing can be allocated on the given node. The default is Decision.ALWAYS.

canRemain

public Decision canRemain(ShardRouting shardRouting,
 RoutingNode node,
 RoutingAllocation allocation)

Returns a Decision whether the given shard routing can be remain on the given node. The default is Decision.ALWAYS.

canAllocate

public Decision canAllocate(ShardRouting shardRouting,
 RoutingAllocation allocation)

Returns a Decision whether the given shard routing can be allocated at all at this state of the RoutingAllocation. The default is Decision.ALWAYS.

canAllocate

public Decision canAllocate(IndexMetadata indexMetadata,
 RoutingNode node,
 RoutingAllocation allocation)

Returns a Decision whether the given shard routing can be allocated at all at this state of the RoutingAllocation. The default is Decision.ALWAYS.

shouldAutoExpandToNode

public Decision shouldAutoExpandToNode(IndexMetadata indexMetadata,
 DiscoveryNode node,
 RoutingAllocation allocation)

Returns a Decision whether shards of the given index should be auto-expanded to this node at this state of the RoutingAllocation. The default is Decision.ALWAYS.

canRebalance

public Decision canRebalance(RoutingAllocation allocation)

Returns a Decision whether the cluster can execute re-balanced operations at all. Decision.ALWAYS.

canForceAllocatePrimary

public Decision canForceAllocatePrimary(ShardRouting shardRouting,
 RoutingNode node,
 RoutingAllocation allocation)

Returns a Decision whether the given primary shard can be forcibly allocated on the given node. This method should only be called for unassigned primary shards where the node has a shard copy on disk. Note: all implementations that override this behavior should take into account the results of canAllocate(ShardRouting, RoutingNode, RoutingAllocation) before making a decision on force allocation, because force allocation should only be considered if all deciders return Decision.NO.