io.zeebe.logstreams.spi

Interface SnapshotController

All Known Implementing Classes:

FsSnapshotController, StateSnapshotController

public interface SnapshotController

Method Summary

Modifier and Type	Method and Description
default void	purgeAll() Purges all snapshots.
void	purgeAll(java.util.function.Predicate<StateSnapshotMetadata> matcher) Purges all snapshots which return true for the given matcher.
default void	purgeAllExcept(StateSnapshotMetadata metadata) Purges old and invalid snapshots.
StateSnapshotMetadata	recover(long commitPosition, int term, java.util.function.Predicate<StateSnapshotMetadata> filter) Recovers the state from the latest snapshot and returns the corresponding metadata.
void	takeSnapshot(StateSnapshotMetadata metadata) Takes a snapshot based on the given metadata: - last successful processed event - last written event (regardless of whether or not it is committed) - term of the last written event
default void	takeSnapshot(StateSnapshotMetadata metadata, long commitPosition) Temporary addition to add commitPosition to parameters, will be removed since it's only useful for FsSnapshotController.

Method Detail

takeSnapshot

void takeSnapshot(StateSnapshotMetadata metadata)
           throws Exception

Takes a snapshot based on the given metadata: - last successful processed event - last written event (regardless of whether or not it is committed) - term of the last written event

Parameters:

metadata - current state metadata

Throws:

Exception

takeSnapshot

default void takeSnapshot(StateSnapshotMetadata metadata,
                          long commitPosition)
                   throws Exception

Temporary addition to add commitPosition to parameters, will be removed since it's only useful for FsSnapshotController.

Parameters:

metadata - current state metadata

commitPosition - temporary parameter, to be removed once Fs package is removed

Throws:

Exception

recover

StateSnapshotMetadata recover(long commitPosition,
                              int term,
                              java.util.function.Predicate<StateSnapshotMetadata> filter)
                       throws Exception

Recovers the state from the latest snapshot and returns the corresponding metadata. The metadata is used by the StreamProcessController to know where to seek to in the log stream. Defaults to: (-1, -1, term)

Parameters:

commitPosition - current log stream commit position

Returns:

recovered state metadata

Throws:

Exception

purgeAll

void purgeAll(java.util.function.Predicate<StateSnapshotMetadata> matcher)
       throws Exception

Purges all snapshots which return true for the given matcher.

Parameters:

matcher - predicate used to match

Throws:

Exception

purgeAll

default void purgeAll()
               throws Exception

Purges all snapshots.

Throws:

Exception

purgeAllExcept

default void purgeAllExcept(StateSnapshotMetadata metadata)
                     throws Exception

Purges old and invalid snapshots. Should be done once we are sure we can discard other snapshots, e.g. during recovery.

Parameters:

metadata - last taken/recovered snapshot metadata

Throws:

Exception