Package org.elasticsearch.gateway

Class PrimaryShardAllocator

java.lang.Object

org.elasticsearch.gateway.BaseGatewayShardAllocator

org.elasticsearch.gateway.PrimaryShardAllocator

public abstract class PrimaryShardAllocator
extends BaseGatewayShardAllocator

The primary shard allocator allocates unassigned primary shards to nodes that hold valid copies of the unassigned primaries. It does this by iterating over all unassigned primary shards in the routing table and fetching shard metadata from each node in the cluster that holds a copy of the shard. The shard metadata from each node is compared against the set of valid allocation IDs and for all valid shard copies (if any), the primary shard allocator executes the allocation deciders to chose a copy to assign the primary shard to. Note that the PrimaryShardAllocator does *not* allocate primaries on index creation (see BalancedShardsAllocator), nor does it allocate primaries when a primary shard failed and there is a valid replica copy that can immediately be promoted to primary, as this takes place in RoutingNodes.failShard(org.apache.logging.log4j.Logger, org.elasticsearch.cluster.routing.ShardRouting, org.elasticsearch.cluster.routing.UnassignedInfo, org.elasticsearch.cluster.metadata.IndexMetadata, org.elasticsearch.cluster.routing.RoutingChangesObserver).

Field Summary

Fields inherited from class org.elasticsearch.gateway.BaseGatewayShardAllocator

logger

Constructor Summary

Constructors

Constructor	Description
PrimaryShardAllocator()

Method Summary

Modifier and Type	Method	Description
protected static org.elasticsearch.gateway.PrimaryShardAllocator.NodeShardsResult	buildNodeShardsResult(ShardRouting shard, boolean matchAnyShard, Set<String> ignoreNodes, Set<String> inSyncAllocationIds, AsyncShardFetch.FetchResult<TransportNodesListGatewayStartedShards.NodeGatewayStartedShards> shardState, org.apache.logging.log4j.Logger logger)	Builds a list of nodes.
protected abstract AsyncShardFetch.FetchResult<TransportNodesListGatewayStartedShards.NodeGatewayStartedShards>	fetchData(ShardRouting shard, RoutingAllocation allocation)
AllocateUnassignedDecision	makeAllocationDecision(ShardRouting unassignedShard, RoutingAllocation allocation, org.apache.logging.log4j.Logger logger)	Make a decision on the allocation of an unassigned shard.

Methods inherited from class org.elasticsearch.gateway.BaseGatewayShardAllocator

allocateUnassigned, buildDecisionsForAllNodes, getExpectedShardSize

Methods inherited from class java.lang.Object

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

Constructor Details

PrimaryShardAllocator

public PrimaryShardAllocator()

Method Details

makeAllocationDecision

public AllocateUnassignedDecision makeAllocationDecision(ShardRouting unassignedShard,
 RoutingAllocation allocation,
 org.apache.logging.log4j.Logger logger)

Description copied from class: BaseGatewayShardAllocator

Make a decision on the allocation of an unassigned shard. This method is used by BaseGatewayShardAllocator.allocateUnassigned(ShardRouting, RoutingAllocation, ExistingShardsAllocator.UnassignedAllocationHandler) to make decisions about whether or not the shard can be allocated by this allocator and if so, to which node it will be allocated.

Specified by:

makeAllocationDecision in class BaseGatewayShardAllocator

Parameters:

unassignedShard - the unassigned shard to allocate

allocation - the current routing state

logger - the logger

Returns:

an AllocateUnassignedDecision with the final decision of whether to allocate and details of the decision

buildNodeShardsResult

protected static org.elasticsearch.gateway.PrimaryShardAllocator.NodeShardsResult buildNodeShardsResult(ShardRouting shard,
 boolean matchAnyShard,
 Set<String> ignoreNodes,
 Set<String> inSyncAllocationIds,
 AsyncShardFetch.FetchResult<TransportNodesListGatewayStartedShards.NodeGatewayStartedShards> shardState,
 org.apache.logging.log4j.Logger logger)

Builds a list of nodes. If matchAnyShard is set to false, only nodes that have an allocation id matching inSyncAllocationIds are added to the list. Otherwise, any node that has a shard is added to the list, but entries with matching allocation id are always at the front of the list.

fetchData

protected abstract AsyncShardFetch.FetchResult<TransportNodesListGatewayStartedShards.NodeGatewayStartedShards> fetchData(ShardRouting shard,
 RoutingAllocation allocation)