K- type of the backend keys.
public class RocksIncrementalSnapshotStrategy<K> extends RocksDBSnapshotStrategyBase<K,org.apache.flink.contrib.streaming.state.snapshot.RocksIncrementalSnapshotStrategy.IncrementalRocksDBSnapshotResources>
RocksDBKeyedStateBackendthat is based on RocksDB's native checkpoints and creates incremental snapshots.
|Constructor and Description|
|Modifier and Type||Method and Description|
This method is called as a notification once a distributed checkpoint has been aborted.
Notifies the listener that the checkpoint with the given
Performs the synchronous part of the snapshot.
public RocksIncrementalSnapshotStrategy(@Nonnull org.rocksdb.RocksDB db, @Nonnull ResourceGuard rocksDBResourceGuard, @Nonnull TypeSerializer<K> keySerializer, @Nonnull LinkedHashMap<String,RocksDBKeyedStateBackend.RocksDbKvStateInfo> kvStateInformation, @Nonnull KeyGroupRange keyGroupRange, @Nonnegative int keyGroupPrefixBytes, @Nonnull LocalRecoveryConfig localRecoveryConfig, @Nonnull CloseableRegistry cancelStreamRegistry, @Nonnull File instanceBasePath, @Nonnull UUID backendUID, @Nonnull SortedMap<Long,Set<StateHandleID>> materializedSstFiles, @Nonnull RocksDBStateUploader rocksDBStateUploader, long lastCompletedCheckpointId)
public org.apache.flink.contrib.streaming.state.snapshot.RocksIncrementalSnapshotStrategy.IncrementalRocksDBSnapshotResources syncPrepareResources(long checkpointId) throws Exception
checkpointId- The ID of the checkpoint.
public SnapshotStrategy.SnapshotResultSupplier<KeyedStateHandle> asyncSnapshot(org.apache.flink.contrib.streaming.state.snapshot.RocksIncrementalSnapshotStrategy.IncrementalRocksDBSnapshotResources snapshotResources, long checkpointId, long timestamp, @Nonnull CheckpointStreamFactory checkpointStreamFactory, @Nonnull CheckpointOptions checkpointOptions)
CheckpointStreamFactoryand returns a @
SupplierWithExceptionthat gives a state handle to the snapshot.
checkpointId- The ID of the checkpoint.
timestamp- The timestamp of the checkpoint.
checkpointStreamFactory- The factory that we can use for writing our state to streams.
checkpointOptions- Options for how to perform this checkpoint.
public void notifyCheckpointComplete(long completedCheckpointId)
checkpointIdcompleted and was committed.
These notifications are "best effort", meaning they can sometimes be skipped. To behave
properly, implementers need to follow the "Checkpoint Subsuming Contract". Please see the
class-level JavaDocs for details.
Please note that checkpoints may generally overlap, so you cannot assume that the
notifyCheckpointComplete() call is always for the latest prior checkpoint (or snapshot) that
was taken on the function/operator implementing this interface. It might be for a checkpoint
that was triggered earlier. Implementing the "Checkpoint Subsuming Contract" (see above)
properly handles this situation correctly as well.
Please note that throwing exceptions from this method will not cause the completed checkpoint to be revoked. Throwing exceptions will typically cause task/job failure and trigger recovery.
completedCheckpointId- The ID of the checkpoint that has been completed.
public void notifyCheckpointAborted(long abortedCheckpointId)
Important: The fact that a checkpoint has been aborted does NOT mean that the data
and artifacts produced between the previous checkpoint and the aborted checkpoint are to be
discarded. The expected behavior is as if this checkpoint was never triggered in the first
place, and the next successful checkpoint simply covers a longer time span. See the
"Checkpoint Subsuming Contract" in the
class-level JavaDocs for
These notifications are "best effort", meaning they can sometimes be skipped.
This method is very rarely necessary to implement. The "best effort" guarantee, together with the fact that this method should not result in discarding any data (per the "Checkpoint Subsuming Contract") means it is mainly useful for earlier cleanups of auxiliary resources. One example is to pro-actively clear a local per-checkpoint state cache upon checkpoint failure.
abortedCheckpointId- The ID of the checkpoint that has been aborted.
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