Package io.camunda.zeebe.snapshots.impl

Class FileBasedSnapshotStore

java.lang.Object

io.camunda.zeebe.scheduler.Actor

io.camunda.zeebe.snapshots.impl.FileBasedSnapshotStore

All Implemented Interfaces:

AsyncClosable, ConcurrencyControl, ConstructableSnapshotStore, PersistedSnapshotStore, ReceivableSnapshotStore, RestorableSnapshotStore, CloseableSilently, AutoCloseable, Executor

public final class FileBasedSnapshotStore
extends Actor
implements ConstructableSnapshotStore, ReceivableSnapshotStore, RestorableSnapshotStore

Nested Class Summary

Nested classes/interfaces inherited from class io.camunda.zeebe.scheduler.Actor

Actor.ActorBuilder

Field Summary

Fields

Modifier and Type	Field	Description
static final String	PENDING_DIRECTORY
static final String	SNAPSHOTS_DIRECTORY

Fields inherited from class io.camunda.zeebe.scheduler.Actor

actor, ACTOR_PROP_NAME, ACTOR_PROP_PARTITION_ID

Constructor Summary

Constructors

Constructor	Description
FileBasedSnapshotStore(int partitionId, Path root)
FileBasedSnapshotStore(int partitionId, Path root, ChecksumProvider checksumProvider)

Method Summary

Modifier and Type	Method	Description
ActorFuture<Boolean>	addSnapshotListener(PersistedSnapshotListener listener)	Adds an PersistedSnapshotListener to the store, which is notified when a new PersistedSnapshot is persisted at this store.
protected Map<String,String>	createContext()
ActorFuture<Void>	delete()	Deletes a PersistedSnapshotStore from disk.
ActorFuture<Set<PersistedSnapshot>>	getAvailableSnapshots()	Returns a set of all available snapshots.
ActorFuture<Long>	getCompactionBound()	Returns the lowest compaction bound of all available snapshots.
long	getCurrentSnapshotIndex()
Optional<PersistedSnapshot>	getLatestSnapshot()
String	getName()
Path	getPath()
boolean	hasSnapshotId(String id)	Returns true if the given identifier is equal to the snapshot id of the current persisted snapshot, false otherwise.
ActorFuture<FileBasedReceivedSnapshot>	newReceivedSnapshot(String snapshotId)	Starts a new received volatile snapshot which can be persisted later.
Either<SnapshotException,TransientSnapshot>	newTransientSnapshot(long index, long term, long processedPosition, long exportedPosition)	Starts a new transient snapshot which can be persisted after the snapshot was taken.
protected void	onActorClosing()
protected void	onActorStarting()
ActorFuture<Void>	purgePendingSnapshots()	Purges all ongoing pending/transient/volatile snapshots.
ActorFuture<Boolean>	removeSnapshotListener(PersistedSnapshotListener listener)	Removes an registered PersistedSnapshotListener from the store.
void	restore(String snapshotId, Map<String,Path> snapshotFiles)	Restores the snapshot by moving the snapshotFiles to the snapshotDirectory.
String	toString()

Methods inherited from class io.camunda.zeebe.scheduler.Actor

buildActorName, call, close, closeAsync, getContext, handleFailure, isActorClosed, newActor, onActorClosed, onActorCloseRequested, onActorFailed, onActorStarted, run, runOnCompletion, schedule, wrap

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.camunda.zeebe.util.CloseableSilently

close

Methods inherited from interface io.camunda.zeebe.scheduler.ConcurrencyControl

createCompletedFuture, createFuture, execute

Field Details

SNAPSHOTS_DIRECTORY

public static final String SNAPSHOTS_DIRECTORY

See Also:

• Constant Field Values

PENDING_DIRECTORY

public static final String PENDING_DIRECTORY

See Also:

• Constant Field Values

Constructor Details

FileBasedSnapshotStore

public FileBasedSnapshotStore(int partitionId,
 Path root)

FileBasedSnapshotStore

public FileBasedSnapshotStore(int partitionId,
 Path root,
 ChecksumProvider checksumProvider)

Method Details

createContext

protected Map<String,String> createContext()

Overrides:

createContext in class Actor

getName

public String getName()

Overrides:

getName in class Actor

onActorStarting

protected void onActorStarting()

Overrides:

onActorStarting in class Actor

onActorClosing

protected void onActorClosing()

Overrides:

onActorClosing in class Actor

hasSnapshotId

public boolean hasSnapshotId(String id)

Description copied from interface: PersistedSnapshotStore

Returns true if the given identifier is equal to the snapshot id of the current persisted snapshot, false otherwise.

Specified by:

hasSnapshotId in interface PersistedSnapshotStore

Parameters:

id - the snapshot Id to look for

Returns:

true if the current snapshot has the equal Id, false otherwise

See Also:

• SnapshotId.getSnapshotIdAsString()

getLatestSnapshot

public Optional<PersistedSnapshot> getLatestSnapshot()

Specified by:

getLatestSnapshot in interface PersistedSnapshotStore

Returns:

the latest PersistedSnapshot if exists

getAvailableSnapshots

public ActorFuture<Set<PersistedSnapshot>> getAvailableSnapshots()

Description copied from interface: PersistedSnapshotStore

Returns a set of all available snapshots.

Specified by:

getAvailableSnapshots in interface PersistedSnapshotStore

getCompactionBound

public ActorFuture<Long> getCompactionBound()

Description copied from interface: PersistedSnapshotStore

Returns the lowest compaction bound of all available snapshots.

Specified by:

getCompactionBound in interface PersistedSnapshotStore

purgePendingSnapshots

public ActorFuture<Void> purgePendingSnapshots()

Description copied from interface: PersistedSnapshotStore

Purges all ongoing pending/transient/volatile snapshots.

Specified by:

purgePendingSnapshots in interface PersistedSnapshotStore

Returns:

future which will be completed when all pending snapshots are deleted

addSnapshotListener

public ActorFuture<Boolean> addSnapshotListener(PersistedSnapshotListener listener)

Description copied from interface: PersistedSnapshotStore

Adds an PersistedSnapshotListener to the store, which is notified when a new PersistedSnapshot is persisted at this store.

Specified by:

addSnapshotListener in interface PersistedSnapshotStore

Parameters:

listener - the listener which should be added and notified later

removeSnapshotListener

public ActorFuture<Boolean> removeSnapshotListener(PersistedSnapshotListener listener)

Description copied from interface: PersistedSnapshotStore

Removes an registered PersistedSnapshotListener from the store. The listener will no longer called when a new PersistedSnapshot is persisted at this store.

Specified by:

removeSnapshotListener in interface PersistedSnapshotStore

Parameters:

listener - the listener which should be removed

getCurrentSnapshotIndex

public long getCurrentSnapshotIndex()

Specified by:

getCurrentSnapshotIndex in interface PersistedSnapshotStore

Returns:

the snapshot index of the latest PersistedSnapshot

See Also:

• PersistedSnapshotStore.getLatestSnapshot()

delete

public ActorFuture<Void> delete()

Description copied from interface: PersistedSnapshotStore

Deletes a PersistedSnapshotStore from disk.

The snapshot store will be deleted by simply reading snapshot file names from disk and deleting snapshot files directly. Deleting the snapshot store does not involve reading any snapshot files into memory.

Specified by:

delete in interface PersistedSnapshotStore

getPath

public Path getPath()

Specified by:

getPath in interface PersistedSnapshotStore

newReceivedSnapshot

public ActorFuture<FileBasedReceivedSnapshot> newReceivedSnapshot(String snapshotId)

Description copied from interface: ReceivableSnapshotStore

Starts a new received volatile snapshot which can be persisted later.

Specified by:

newReceivedSnapshot in interface ReceivableSnapshotStore

Parameters:

snapshotId - the snapshot id which is defined as index-term-timestamp-processedposition-exportedposition

Returns:

the new volatile received snapshot

newTransientSnapshot

public Either<SnapshotException,TransientSnapshot> newTransientSnapshot(long index,
 long term,
 long processedPosition,
 long exportedPosition)

Description copied from interface: ConstructableSnapshotStore

Starts a new transient snapshot which can be persisted after the snapshot was taken.

Specified by:

newTransientSnapshot in interface ConstructableSnapshotStore

Parameters:

index - the index to which the snapshot corresponds to

term - the term to which the snapshots corresponds to

processedPosition - the processed position in the snapshot

exportedPosition - the exported position in the snapshot

Returns:

either an exception or transientSnapshot, if it was taken successfully.

toString

public String toString()

Overrides:

toString in class Object

restore

public void restore(String snapshotId,
 Map<String,Path> snapshotFiles)
             throws IOException

Description copied from interface: RestorableSnapshotStore

Restores the snapshot by moving the snapshotFiles to the snapshotDirectory.

WARN. Implementation of this method can be not thread safe.

Specified by:

restore in interface RestorableSnapshotStore

Parameters:

snapshotId -

snapshotFiles -

Throws:

IOException