org.elasticsearch.snapshots

Class SnapshotsService

java.lang.Object

org.elasticsearch.common.component.AbstractComponent

org.elasticsearch.common.component.AbstractLifecycleComponent<SnapshotsService>

org.elasticsearch.snapshots.SnapshotsService

All Implemented Interfaces:

AutoCloseable, ClusterStateListener, LifecycleComponent<SnapshotsService>, Releasable

public class SnapshotsService
extends AbstractLifecycleComponent<SnapshotsService>
implements ClusterStateListener

Service responsible for creating snapshots

A typical snapshot creating process looks like this:

• On the master node the createSnapshot(SnapshotRequest, CreateSnapshotListener) is called and makes sure that no snapshots is currently running and registers the new snapshot in cluster state
• When cluster state is updated the beginSnapshot(ClusterState, SnapshotMetaData.Entry, boolean, CreateSnapshotListener) method kicks in and initializes the snapshot in the repository and then populates list of shards that needs to be snapshotted in cluster state
• Each data node is watching for these shards and when new shards scheduled for snapshotting appear in the cluster state, data nodes start processing them through processIndexShardSnapshots(org.elasticsearch.cluster.ClusterChangedEvent) method
• Once shard snapshot is created data node updates state of the shard in the cluster state using the updateIndexShardSnapshotStatus(UpdateIndexShardSnapshotStatusRequest) method
• When last shard is completed master node in innerUpdateSnapshotState(org.elasticsearch.snapshots.SnapshotsService.UpdateIndexShardSnapshotStatusRequest) method marks the snapshot as completed
• After cluster state is updated, the endSnapshot(SnapshotMetaData.Entry) finalizes snapshot in the repository, notifies all snapshotCompletionListeners that snapshot is completed, and finally calls removeSnapshotFromClusterState(SnapshotId, SnapshotInfo, Throwable) to remove snapshot from cluster state

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	SnapshotsService.CreateSnapshotListener Listener for create snapshot operation
static interface	SnapshotsService.DeleteSnapshotListener Listener for delete snapshot operation
static interface	SnapshotsService.SnapshotCompletionListener
static class	SnapshotsService.SnapshotRequest Snapshot creation request

Field Summary

Fields

Modifier and Type	Field and Description
static String	UPDATE_SNAPSHOT_ACTION_NAME

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

lifecycle

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

componentSettings, logger, settings

Constructor Summary

Constructors

Constructor and Description
SnapshotsService(Settings settings, ClusterService clusterService, RepositoriesService repositoriesService, ThreadPool threadPool, IndicesService indicesService, TransportService transportService)

Method Summary

Modifier and Type	Method and Description
void	addListener(SnapshotsService.SnapshotCompletionListener listener) Adds snapshot completion listener
void	clusterChanged(ClusterChangedEvent event) Called when cluster state changes.
void	createSnapshot(SnapshotsService.SnapshotRequest request, SnapshotsService.CreateSnapshotListener listener) Initializes the snapshotting process.
com.google.common.collect.ImmutableList<SnapshotMetaData.Entry>	currentSnapshots(String repository, String[] snapshots) Returns status of the currently running snapshots
com.google.common.collect.ImmutableMap<ShardId,IndexShardSnapshotStatus>	currentSnapshotShards(SnapshotId snapshotId) Returns status of shards that are snapshotted on the node and belong to the given snapshot
void	deleteSnapshot(SnapshotId snapshotId, SnapshotsService.DeleteSnapshotListener listener) Deletes snapshot from repository.
protected void	doClose()
protected void	doStart()
protected void	doStop()
static boolean	isRepositoryInUse(ClusterState clusterState, String repository) Checks if a repository is currently in use by one of the snapshots
void	removeListener(SnapshotsService.SnapshotCompletionListener listener) Removes snapshot completion listener
Snapshot	snapshot(SnapshotId snapshotId) Retrieves snapshot from repository
com.google.common.collect.ImmutableList<Snapshot>	snapshots(String repositoryName) Returns a list of snapshots from repository sorted by snapshot creation date
com.google.common.collect.ImmutableMap<ShardId,IndexShardSnapshotStatus>	snapshotShards(SnapshotId snapshotId) Returns status of shards currently finished snapshots

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

addLifecycleListener, close, lifecycleState, removeLifecycleListener, start, stop

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

nodeName

Methods inherited from class java.lang.Object

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

Field Detail

UPDATE_SNAPSHOT_ACTION_NAME

public static final String UPDATE_SNAPSHOT_ACTION_NAME

See Also:

Constant Field Values

Constructor Detail

SnapshotsService

@Inject
public SnapshotsService(Settings settings,
                                ClusterService clusterService,
                                RepositoriesService repositoriesService,
                                ThreadPool threadPool,
                                IndicesService indicesService,
                                TransportService transportService)

Method Detail

snapshot

public Snapshot snapshot(SnapshotId snapshotId)

Retrieves snapshot from repository

Parameters:

snapshotId - snapshot id

Returns:

snapshot

Throws:

SnapshotMissingException - if snapshot is not found

snapshots

public com.google.common.collect.ImmutableList<Snapshot> snapshots(String repositoryName)

Returns a list of snapshots from repository sorted by snapshot creation date

Parameters:

repositoryName - repository name

Returns:

list of snapshots

createSnapshot

public void createSnapshot(SnapshotsService.SnapshotRequest request,
                           SnapshotsService.CreateSnapshotListener listener)

Initializes the snapshotting process.

This method is used by clients to start snapshot. It makes sure that there is no snapshots are currently running and creates a snapshot record in cluster state metadata.

Parameters:

request - snapshot request

listener - snapshot creation listener

currentSnapshots

public com.google.common.collect.ImmutableList<SnapshotMetaData.Entry> currentSnapshots(String repository,
                                                                                        String[] snapshots)

Returns status of the currently running snapshots

This method is executed on master node

Parameters:

repository - repository id

snapshots - optional list of snapshots that will be used as a filter

Returns:

list of metadata for currently running snapshots

currentSnapshotShards

public com.google.common.collect.ImmutableMap<ShardId,IndexShardSnapshotStatus> currentSnapshotShards(SnapshotId snapshotId)

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

This method is executed on data node

Parameters:

snapshotId - snapshot id

Returns:

map of shard id to snapshot status

snapshotShards

public com.google.common.collect.ImmutableMap<ShardId,IndexShardSnapshotStatus> snapshotShards(SnapshotId snapshotId)

Returns status of shards currently finished snapshots

This method is executed on master node and it's complimentary to the currentSnapshotShards(SnapshotId) becuase it returns simliar information but for already finished snapshots.

Parameters:

snapshotId - snapshot id

Returns:

map of shard id to snapshot status

clusterChanged

public void clusterChanged(ClusterChangedEvent event)

Description copied from interface: ClusterStateListener

Called when cluster state changes.

Specified by:

clusterChanged in interface ClusterStateListener

deleteSnapshot

public void deleteSnapshot(SnapshotId snapshotId,
                           SnapshotsService.DeleteSnapshotListener listener)

Deletes snapshot from repository.

If the snapshot is still running cancels the snapshot first and then deletes it from the repository.

Parameters:

snapshotId - snapshot id

listener - listener

isRepositoryInUse

public static boolean isRepositoryInUse(ClusterState clusterState,
                                        String repository)

Checks if a repository is currently in use by one of the snapshots

Parameters:

clusterState - cluster state

repository - repository id

Returns:

true if repository is currently in use by one of the running snapshots

addListener

public void addListener(SnapshotsService.SnapshotCompletionListener listener)

Adds snapshot completion listener

Parameters:

listener - listener

removeListener

public void removeListener(SnapshotsService.SnapshotCompletionListener listener)

Removes snapshot completion listener

Parameters:

listener - listener

doStart

protected void doStart()
                throws ElasticsearchException

Specified by:

doStart in class AbstractLifecycleComponent<SnapshotsService>

Throws:

ElasticsearchException

doStop

protected void doStop()
               throws ElasticsearchException

Specified by:

doStop in class AbstractLifecycleComponent<SnapshotsService>

Throws:

ElasticsearchException

doClose

protected void doClose()
                throws ElasticsearchException

Specified by:

doClose in class AbstractLifecycleComponent<SnapshotsService>

Throws:

ElasticsearchException