Package org.elasticsearch.snapshots

Class SnapshotsService

java.lang.Object

org.elasticsearch.common.component.AbstractLifecycleComponent

org.elasticsearch.snapshots.SnapshotsService

All Implemented Interfaces:

Closeable, AutoCloseable, ClusterStateApplier, LifecycleComponent, Releasable

public class SnapshotsService
extends AbstractLifecycleComponent
implements ClusterStateApplier

Service responsible for creating snapshots

A typical snapshot creating process looks like this:

• On the master node the createSnapshot(CreateSnapshotRequest, ActionListener) is called and makes sure that no snapshot is currently running and registers the new snapshot in cluster state
• When cluster state is updated the beginSnapshot(ClusterState, SnapshotsInProgress.Entry, boolean, ActionListener) 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 SnapshotShardsService.startNewSnapshots(org.elasticsearch.cluster.SnapshotsInProgress) method
• Once shard snapshot is created data node updates state of the shard in the cluster state using the SnapshotShardsService.sendSnapshotShardUpdate(Snapshot, ShardId, ShardSnapshotStatus) method
• When last shard is completed master node in SnapshotShardsService.innerUpdateSnapshotState(org.elasticsearch.snapshots.SnapshotShardsService.UpdateIndexShardSnapshotStatusRequest, org.elasticsearch.action.ActionListener<org.elasticsearch.snapshots.SnapshotShardsService.UpdateIndexShardSnapshotStatusResponse>) method marks the snapshot as completed
• After cluster state is updated, the endSnapshot(SnapshotsInProgress.Entry, MetaData) finalizes snapshot in the repository, notifies all snapshotCompletionListeners that snapshot is completed, and finally calls removeSnapshotFromClusterState(Snapshot, SnapshotInfo, Exception) to remove snapshot from cluster state

Field Summary

Fields

Modifier and Type	Field	Description
static Version	NO_REPO_INITIALIZE_VERSION	Minimum node version which does not use Repository.initializeSnapshot(SnapshotId, List, MetaData) to write snapshot metadata when starting a snapshot.

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

lifecycle

Constructor Summary

Constructors

Constructor	Description
SnapshotsService(Settings settings, ClusterService clusterService, IndexNameExpressionResolver indexNameExpressionResolver, RepositoriesService repositoriesService, ThreadPool threadPool)

Method Summary

Modifier and Type	Method	Description
void	applyClusterState(ClusterChangedEvent event)	Called when a new cluster state (ClusterChangedEvent.state() needs to be applied.
void	createSnapshot(CreateSnapshotRequest request, ActionListener<Snapshot> listener)	Initializes the snapshotting process.
List<SnapshotInfo>	currentSnapshots(String repositoryName)	Returns a list of currently running snapshots from repository sorted by snapshot creation date
List<SnapshotsInProgress.Entry>	currentSnapshots(String repository, List<String> snapshots)	Returns status of the currently running snapshots
void	deleteSnapshot(String repositoryName, String snapshotName, ActionListener<Void> listener, boolean immediatePriority)	Deletes a snapshot from the repository, looking up the Snapshot reference before deleting.
protected void	doClose()
protected void	doStart()
protected void	doStop()
void	executeSnapshot(CreateSnapshotRequest request, ActionListener<SnapshotInfo> listener)	Same as createSnapshot(CreateSnapshotRequest, ActionListener) but invokes its callback on completion of the snapshot.
RepositoryData	getRepositoryData(String repositoryName)	Gets the RepositoryData for the given repository.
static boolean	isRepositoryInUse(ClusterState clusterState, String repository)	Checks if a repository is currently in use by one of the snapshots
SnapshotInfo	snapshot(String repositoryName, SnapshotId snapshotId)	Retrieves snapshot from repository
List<SnapshotInfo>	snapshots(String repositoryName, List<SnapshotId> snapshotIds, boolean ignoreUnavailable)	Returns a list of snapshots from repository sorted by snapshot creation date
Map<ShardId,IndexShardSnapshotStatus>	snapshotShards(String repositoryName, RepositoryData repositoryData, SnapshotInfo snapshotInfo)	Returns status of shards currently finished snapshots
static Set<Index>	snapshottingIndices(ClusterState currentState, Set<Index> indicesToCheck)	Returns the indices that are currently being snapshotted (with partial == false) and that are contained in the indices-to-check set.

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

addLifecycleListener, close, lifecycleState, removeLifecycleListener, start, stop

Methods inherited from class java.lang.Object

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

Field Detail

NO_REPO_INITIALIZE_VERSION

public static final Version NO_REPO_INITIALIZE_VERSION

Minimum node version which does not use Repository.initializeSnapshot(SnapshotId, List, MetaData) to write snapshot metadata when starting a snapshot.

Constructor Detail

SnapshotsService

public SnapshotsService(Settings settings,
                        ClusterService clusterService,
                        IndexNameExpressionResolver indexNameExpressionResolver,
                        RepositoriesService repositoriesService,
                        ThreadPool threadPool)

Method Detail

getRepositoryData

public RepositoryData getRepositoryData(String repositoryName)

Gets the RepositoryData for the given repository.

Parameters:

repositoryName - repository name

Returns:

repository data

snapshot

public SnapshotInfo snapshot(String repositoryName,
                             SnapshotId snapshotId)

Retrieves snapshot from repository

Parameters:

repositoryName - repository name

snapshotId - snapshot id

Returns:

snapshot

Throws:

SnapshotMissingException - if snapshot is not found

snapshots

public List<SnapshotInfo> snapshots(String repositoryName,
                                    List<SnapshotId> snapshotIds,
                                    boolean ignoreUnavailable)

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

Parameters:

repositoryName - repository name

snapshotIds - snapshots for which to fetch snapshot information

ignoreUnavailable - if true, snapshots that could not be read will only be logged with a warning, if false, they will throw an error

Returns:

list of snapshots

currentSnapshots

public List<SnapshotInfo> currentSnapshots(String repositoryName)

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

Parameters:

repositoryName - repository name

Returns:

list of snapshots

executeSnapshot

public void executeSnapshot(CreateSnapshotRequest request,
                            ActionListener<SnapshotInfo> listener)

Same as createSnapshot(CreateSnapshotRequest, ActionListener) but invokes its callback on completion of the snapshot.

Parameters:

request - snapshot request

listener - snapshot completion listener

createSnapshot

public void createSnapshot(CreateSnapshotRequest request,
                           ActionListener<Snapshot> 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 List<SnapshotsInProgress.Entry> currentSnapshots(String repository,
                                                        List<String> snapshots)

Returns status of the currently running snapshots

This method is executed on master node

Parameters:

repository - repository id

snapshots - list of snapshots that will be used as a filter, empty list means no snapshots are filtered

Returns:

list of metadata for currently running snapshots

snapshotShards

public Map<ShardId,IndexShardSnapshotStatus> snapshotShards(String repositoryName,
                                                                  RepositoryData repositoryData,
                                                                  SnapshotInfo snapshotInfo)
                                                           throws IOException

Returns status of shards currently finished snapshots

This method is executed on master node and it's complimentary to the SnapshotShardsService.currentSnapshotShards(Snapshot) because it returns similar information but for already finished snapshots.

Parameters:

repositoryName - repository name

snapshotInfo - snapshot info

Returns:

map of shard id to snapshot status

Throws:

IOException

applyClusterState

public void applyClusterState(ClusterChangedEvent event)

Description copied from interface: ClusterStateApplier

Called when a new cluster state (ClusterChangedEvent.state() needs to be applied. The cluster state to be applied is already committed when this method is called, so an applier must therefore be prepared to deal with any state it receives without throwing an exception. Throwing an exception from an applier is very bad because it will stop the application of this state before it has reached all the other appliers, and will likely result in another attempt to apply the same (or very similar) cluster state which might continue until this node is removed from the cluster.

Specified by:

applyClusterState in interface ClusterStateApplier

deleteSnapshot

public void deleteSnapshot(String repositoryName,
                           String snapshotName,
                           ActionListener<Void> listener,
                           boolean immediatePriority)

Deletes a snapshot from the repository, looking up the Snapshot reference before deleting. If the snapshot is still running cancels the snapshot first and then deletes it from the repository.

Parameters:

repositoryName - repositoryName

snapshotName - snapshotName

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

snapshottingIndices

public static Set<Index> snapshottingIndices(ClusterState currentState,
                                             Set<Index> indicesToCheck)

Returns the indices that are currently being snapshotted (with partial == false) and that are contained in the indices-to-check set.

doStart

protected void doStart()

Specified by:

doStart in class AbstractLifecycleComponent

doStop

protected void doStop()

Specified by:

doStop in class AbstractLifecycleComponent

doClose

protected void doClose()

Specified by:

doClose in class AbstractLifecycleComponent