Package org.apache.ignite.internal.processors.cache.persistence.snapshot

Interface SnapshotHandler<T>

Type Parameters:

T - Type of the local processing result.

All Superinterfaces:

Extension

All Known Implementing Classes:

DataStreamerUpdatesHandler, SnapshotPartitionsQuickVerifyHandler, SnapshotPartitionsVerifyHandler

public interface SnapshotHandler<T>
extends Extension

Snapshot operation handler.

The execution of the handler consists of two steps:

1. Local call of invoke(SnapshotHandlerContext) method on all nodes containing the snapshot data.
2. Processing the results of local invocations in the complete(String, Collection) method on one of the nodes containing the snapshot data.

Note: If during the execution of a snapshot operation some node exits, then whole operation is rolled back, in which case the complete(String, Collection) method may not be called.

Method Summary

Modifier and Type	Method	Description
default void	complete(String name, Collection<SnapshotHandlerResult<T>> results)	Processing the results of the invoke(SnapshotHandlerContext) method received from all nodes.
T	invoke(SnapshotHandlerContext ctx)	Local processing of a snapshot operation.
SnapshotHandlerType	type()	Snapshot handler type.

Method Detail

type

SnapshotHandlerType type()

Snapshot handler type.

invoke

@Nullable
T invoke(SnapshotHandlerContext ctx)
  throws Exception

Local processing of a snapshot operation. Called on every node that contains snapshot data.

Parameters:

ctx - Snapshot handler context.

Returns:

Result of local processing. This result will be returned in SnapshotHandlerResult.data() method passed into complete(String, Collection) handler method.

Throws:

Exception - If invocation caused an exception. This exception will be returned in SnapshotHandlerResult.error()} method passed into complete(String, Collection) handler method.

complete

default void complete(String name,
                      Collection<SnapshotHandlerResult<T>> results)
               throws SnapshotWarningException,
                      Exception

Processing the results of the invoke(SnapshotHandlerContext) method received from all nodes. This method is called on coordinator node for SnapshotHandlerType.CREATE handler type and on the random node containing the snapshot data for SnapshotHandlerType.RESTORE.

Note: If this method fails, the entire cluster-wide snapshot operation will be aborted and the changes made by it will be rolled back.

Parameters:

name - Snapshot name.

results - Results from all nodes.

Throws:

SnapshotWarningException - If a warning of snapshot operation occurred.

Exception - If the snapshot operation needs to be aborted.

See Also:

SnapshotHandlerResult