Module org.elasticsearch.server

Package org.elasticsearch.snapshots

Class SnapshotShardsService

java.lang.Object

org.elasticsearch.common.component.AbstractLifecycleComponent

org.elasticsearch.snapshots.SnapshotShardsService

All Implemented Interfaces:

Closeable, AutoCloseable, ClusterStateListener, LifecycleComponent, Releasable, IndexEventListener

public final class SnapshotShardsService
extends AbstractLifecycleComponent
implements ClusterStateListener, IndexEventListener

This service runs on data nodes and controls currently running shard snapshots on these nodes. It is responsible for starting and stopping shard level snapshots. See package level documentation of org.elasticsearch.snapshots for details. See SnapshotsService for the master node snapshotting steps.

Field Summary

Fields inherited from class org.elasticsearch.common.component.AbstractLifecycleComponent

lifecycle

Constructor Summary

Constructors

Constructor	Description
SnapshotShardsService(Settings settings, ClusterService clusterService, RepositoriesService repositoriesService, TransportService transportService, IndicesService indicesService)

Method Summary

Modifier and Type	Method	Description
void	beforeIndexShardClosed(ShardId shardId, IndexShard indexShard, Settings indexSettings)	Called before the index shard gets closed.
void	clusterChanged(ClusterChangedEvent event)	Called when cluster state changes.
Map<ShardId,IndexShardSnapshotStatus.Copy>	currentSnapshotShards(Snapshot snapshot)	Returns status of shards that are snapshotted on the node and belong to the given snapshot
protected void	doClose()	Close this component.
protected void	doStart()	Start this component.
protected void	doStop()	Stop this component.
static String	getShardStateId(IndexShard indexShard, org.apache.lucene.index.IndexCommit snapshotIndexCommit)	Generates an identifier from the current state of a shard that can be used to detect whether a shard's contents have changed between two snapshots.

Methods inherited from class org.elasticsearch.common.component.AbstractLifecycleComponent

addLifecycleListener, close, lifecycleState, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.elasticsearch.index.shard.IndexEventListener

afterFilesRestoredFromRepository, afterIndexCreated, afterIndexRemoved, afterIndexShardClosed, afterIndexShardClosing, afterIndexShardCreated, afterIndexShardDeleted, afterIndexShardRecovery, afterIndexShardStarted, beforeIndexAddedToCluster, beforeIndexCreated, beforeIndexRemoved, beforeIndexShardCreated, beforeIndexShardDeleted, beforeIndexShardRecovery, indexShardStateChanged, onStoreClosed, onStoreCreated, shardRoutingChanged

Constructor Details

SnapshotShardsService

public SnapshotShardsService(Settings settings,
 ClusterService clusterService,
 RepositoriesService repositoriesService,
 TransportService transportService,
 IndicesService indicesService)

Method Details

doStart

protected void doStart()

Description copied from class: AbstractLifecycleComponent

Start this component. Typically that means doing things like launching background processes and registering listeners on other components. Other components have been initialized by this point, but may not yet be started.

If this method throws an exception then the startup process will fail, but this component will not be stopped before it is closed.

This method is called while synchronized on AbstractLifecycleComponent.lifecycle. It is only called once in the lifetime of a component, although it may not be called at all if the startup process encountered some kind of fatal error, such as the failure of some other component to initialize or start.

Specified by:

doStart in class AbstractLifecycleComponent

doStop

protected void doStop()

Description copied from class: AbstractLifecycleComponent

Stop this component. Typically that means doing the reverse of whatever AbstractLifecycleComponent.doStart() does.

This method is called while synchronized on AbstractLifecycleComponent.lifecycle. It is only called once in the lifetime of a component, after calling AbstractLifecycleComponent.doStart(), although it will not be called at all if this component did not successfully start.

Specified by:

doStop in class AbstractLifecycleComponent

doClose

protected void doClose()

Description copied from class: AbstractLifecycleComponent

Close this component. Typically that means doing the reverse of whatever happened during initialization, such as releasing resources acquired there.

This method is called while synchronized on AbstractLifecycleComponent.lifecycle. It is called once in the lifetime of a component. If the component was started then it will be stopped before it is closed, and once it is closed it will not be started or stopped.

Specified by:

doClose in class AbstractLifecycleComponent

clusterChanged

public void clusterChanged(ClusterChangedEvent event)

Description copied from interface: ClusterStateListener

Called when cluster state changes.

Cluster states are applied one-by-one which means they can be a performance bottleneck. Implementations of this method should therefore be fast, so please consider forking work into the background rather than doing everything inline.

Specified by:

clusterChanged in interface ClusterStateListener

beforeIndexShardClosed

public void beforeIndexShardClosed(ShardId shardId,
 @Nullable
 IndexShard indexShard,
 Settings indexSettings)

Description copied from interface: IndexEventListener

Called before the index shard gets closed.

Specified by:

beforeIndexShardClosed in interface IndexEventListener

Parameters:

indexShard - The index shard

currentSnapshotShards

public Map<ShardId,IndexShardSnapshotStatus.Copy> currentSnapshotShards(Snapshot snapshot)

Returns status of shards that are snapshotted on the node and belong to the given snapshot

This method is executed on data node

Parameters:

snapshot - snapshot

Returns:

map of shard id to snapshot status

getShardStateId

@Nullable
public static String getShardStateId(IndexShard indexShard,
 org.apache.lucene.index.IndexCommit snapshotIndexCommit)
                              throws IOException

Generates an identifier from the current state of a shard that can be used to detect whether a shard's contents have changed between two snapshots. A shard is assumed to have unchanged contents if its global- and local checkpoint are equal, its maximum sequence number has not changed and its history- and force-merge-uuid have not changed. The method returns null if global and local checkpoint are different for a shard since no safe unique shard state id can be used in this case because of the possibility of a primary failover leading to different shard content for the same sequence number on a subsequent snapshot.

Parameters:

indexShard - Shard

snapshotIndexCommit - IndexCommit for shard

Returns:

shard state id or null if none can be used

Throws:

IOException