Package org.elasticsearch.cluster.routing.allocation.allocator

Class BalancedShardsAllocator.Balancer

java.lang.Object

org.elasticsearch.cluster.routing.allocation.allocator.BalancedShardsAllocator.Balancer

Enclosing class:

BalancedShardsAllocator

public static class BalancedShardsAllocator.Balancer
extends Object

A BalancedShardsAllocator.Balancer

Constructor Summary

Constructors

Constructor	Description
Balancer(org.apache.logging.log4j.Logger logger, RoutingAllocation allocation, BalancedShardsAllocator.WeightFunction weight, float threshold)

Method Summary

Modifier and Type	Method	Description
float	avgShardsPerNode()	Returns the global average of shards per node
float	avgShardsPerNode(String index)	Returns the average of shards per node for the given index
MoveDecision	decideMove(ShardRouting shardRouting)	Makes a decision on whether to move a started shard to another node.
void	moveShards()	Move started shards that can not be allocated to a node anymore For each shard to be moved this function executes a move operation to the minimal eligible node with respect to the weight function.

Methods inherited from class java.lang.Object

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

Constructor Detail

Balancer

public Balancer(org.apache.logging.log4j.Logger logger,
                RoutingAllocation allocation,
                BalancedShardsAllocator.WeightFunction weight,
                float threshold)

Method Detail

avgShardsPerNode

public float avgShardsPerNode(String index)

Returns the average of shards per node for the given index

avgShardsPerNode

public float avgShardsPerNode()

Returns the global average of shards per node

moveShards

public void moveShards()

Move started shards that can not be allocated to a node anymore For each shard to be moved this function executes a move operation to the minimal eligible node with respect to the weight function. If a shard is moved the shard will be set to ShardRoutingState.RELOCATING and a shadow instance of this shard is created with an incremented version in the state ShardRoutingState.INITIALIZING.

decideMove

public MoveDecision decideMove(ShardRouting shardRouting)

Makes a decision on whether to move a started shard to another node. The following rules apply to the MoveDecision return object: 1. If the shard is not started, no decision will be taken and MoveDecision.isDecisionTaken() will return false. 2. If the shard is allowed to remain on its current node, no attempt will be made to move the shard and MoveDecision.canRemainDecision will have a decision type of YES. All other fields in the object will be null. 3. If the shard is not allowed to remain on its current node, then MoveDecision.getAllocationDecision() will be populated with the decision of moving to another node. If MoveDecision.forceMove() ()} returns true, then AbstractAllocationDecision.targetNode will return a non-null value, otherwise the assignedNodeId will be null. 4. If the method is invoked in explain mode (e.g. from the cluster allocation explain APIs), then AbstractAllocationDecision.nodeDecisions will have a non-null value.