Package org.apache.hadoop.fs.azure

Class SelfRenewingLease

java.lang.Object

org.apache.hadoop.fs.azure.SelfRenewingLease

public class SelfRenewingLease
extends java.lang.Object

An Azure blob lease that automatically renews itself indefinitely using a background thread. Use it to synchronize distributed processes, or to prevent writes to the blob by other processes that don't have the lease. Creating a new Lease object blocks the caller until the Azure blob lease is acquired. Attempting to get a lease on a non-existent blob throws StorageException. Call free() to release the Lease. You can use this Lease like a distributed lock. If the holder process dies, the lease will time out since it won't be renewed.

Field Summary

Fields

Modifier and Type	Field	Description
static int	LEASE_RENEWAL_PERIOD

Constructor Summary

Constructors

Constructor	Description
SelfRenewingLease(org.apache.hadoop.fs.azure.StorageInterface.CloudBlobWrapper blobWrapper, boolean throwIfPresent)

Method Summary

Modifier and Type	Method	Description
void	free()	Free the lease and stop the keep-alive thread.
com.microsoft.azure.storage.blob.CloudBlob	getCloudBlob()
java.lang.String	getLeaseID()
boolean	isFreed()

Methods inherited from class java.lang.Object

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

Field Detail

LEASE_RENEWAL_PERIOD

public static final int LEASE_RENEWAL_PERIOD

See Also:

Constant Field Values

Constructor Detail

SelfRenewingLease

public SelfRenewingLease(org.apache.hadoop.fs.azure.StorageInterface.CloudBlobWrapper blobWrapper,
                         boolean throwIfPresent)
                  throws com.microsoft.azure.storage.StorageException

Throws:

com.microsoft.azure.storage.StorageException

Method Detail

free

public void free()
          throws com.microsoft.azure.storage.StorageException

Free the lease and stop the keep-alive thread.

Throws:

com.microsoft.azure.storage.StorageException - Thrown when fail to free the lease.

isFreed

public boolean isFreed()

getLeaseID

public java.lang.String getLeaseID()

getCloudBlob

public com.microsoft.azure.storage.blob.CloudBlob getCloudBlob()