org.apache.hadoop.fs

Interface BlockStoragePolicySpi

@InterfaceAudience.Public
 @InterfaceStability.Stable
public interface BlockStoragePolicySpi

A storage policy specifies the placement of block replicas on specific storage types.

Method Summary

Modifier and Type	Method and Description
StorageType[]	getCreationFallbacks() Get the fallback storage types for creating new block replicas.
String	getName() Return the name of the storage policy.
StorageType[]	getReplicationFallbacks() Get the fallback storage types for replicating existing block replicas.
StorageType[]	getStorageTypes() Return the preferred storage types associated with this policy.
boolean	isCopyOnCreateFile() Returns true if the policy is inherit-only and cannot be changed for an existing file.

Method Detail

getName

String getName()

Return the name of the storage policy. Policies are uniquely identified by name.

Returns:

the name of the storage policy.

getStorageTypes

StorageType[] getStorageTypes()

Return the preferred storage types associated with this policy. These storage types are used sequentially for successive block replicas.

Returns:

preferred storage types used for placing block replicas.

getCreationFallbacks

StorageType[] getCreationFallbacks()

Get the fallback storage types for creating new block replicas. Fallback storage types are used if the preferred storage types are not available.

Returns:

fallback storage types for new block replicas..

getReplicationFallbacks

StorageType[] getReplicationFallbacks()

Get the fallback storage types for replicating existing block replicas. Fallback storage types are used if the preferred storage types are not available.

Returns:

fallback storage types for replicating existing block replicas.

isCopyOnCreateFile

boolean isCopyOnCreateFile()

Returns true if the policy is inherit-only and cannot be changed for an existing file.

Returns:

true if the policy is inherit-only.