MAINTAINING CACHES OF OBJECT LOCATION INFORMATION IN GATEWAY COMPUTING DEVICES USING MULTICAST MESSAGES

• US 20120259821A1
• Filed: 04/07/2011
• Published: 10/11/2012
• Est. Priority Date: 04/07/2011
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Inventors: Alam, Shahid
• Granted Patent: US 9,094,466 B2
• Time in Patent Office: Days
• US Class Current: 707/692
• CPC Class Codes: G06F 16/1744 using compression, e.g. sparse files
• CPC Class Codes: H04L 12/18 for broadcast or conference , e.g. multicast
• CPC Class Codes: H04L 67/288 Distributed intermediate devices, i.e. intermediate devices for interaction with other intermediate devices on the same level
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

Abstract

Example embodiments relate to maintaining caches of object location information in gateway computing devices using multicast messages. In example embodiments, upon updating a cache with an object identifier and a corresponding object location, a gateway computing device may transmit an update message using a simple multicast transport protocol to a plurality of other gateway computing devices. In contrast, upon deleting an object from a cache, the gateway computing device may transmit a delete message using a reliable multicast transport protocol to the plurality of other gateway computing devices.

Claims

1. A gateway computing device for maintaining a cache of object location information, the gateway computing device comprising:

a storage medium to maintain a cache of object location information; and

a processor to;

receive a first update message transmitted by a first device using a simple multicast transport protocol when a first object is stored, the first update message including a first object identifier and a first storage location,

store the first object identifier and the first storage location in the cache in response to the first update message,

receive a first delete message transmitted by a second device using a reliable multicast transport protocol when a second object is deleted, the first delete message including a second object identifier, and

remove the second object identifier and a corresponding second storage location from the cache in response to the first delete message.

2. The gateway computing device of claim 1, wherein the processor is further configured to:

receive a request to access a third object,

execute a lookup to determine a third storage location of the third object in one of a plurality of storage nodes when a corresponding third object identifier is not located in the cache,

update the cache to include the third object identifier and the third storage location based on the lookup, and

transmit a second update message using the simple multicast transport protocol to a plurality of other gateway computing devices, the second update message instructing the plurality of other gateway computing devices to add the third object identifier and the third storage location to respective caches.

3. The gateway computing device of claim 1, wherein the processor is further configured to:

receive a delete request including a third object identifier f a third object to be deleted from a storage node,

transmit a message instructing the storage node to remove the third object,

remove the third object identifier and a corresponding third storage location from the cache, and

transmit a second delete message using a reliable multicast transport protocol to a plurality of other gateway computing devices, the second delete message instructing the plurality of other gateway computing devices to remove the third object identifier and the third storage location from respective caches.

4. The gateway computing device of claim 1, wherein the processor is further configured to:

remove an expired object identifier from the cache in accordance with a retention policy.

5. The gateway computing device of claim 1, wherein:

the second device is a storage node including storage for a plurality of objects, and

the processor receives the first delete message from the storage node upon deletion of the second object from the storage node based on expiration of a retention policy for the second object.

6. The gateway computing device of claim 1, wherein the gateway computing device is a Hypertext Transfer Protocol (HTTP) portal that responds to HTTP access requests.

7. The gateway computing device of claim 1, wherein:

the first device is a Simple Mail Transfer Protocol (SMTP) portal, and

the processor receives the first update message from the SMTP portal upon storage of a respective email message in a respective storage node by the SMTP portal.

8. A machine-readable storage medium encoded with instructions executable by a processor of a gateway computing device for maintaining a cache of object location information, the machine-readable storage medium comprising:

instructions for updating the cache to include a first object identifier and a corresponding first object location in a storage node;

instructions for transmitting an update message using a simple multicast transport protocol to a plurality of other gateway computing devices, the update message instructing the plurality of other gateway computing devices to add the first object identifier and the first object location to respective caches;

instructions for removing a second object identifier and a corresponding second object location from the cache; and

instructions for transmitting a delete message using a reliable multicast transport protocol to the plurality of other gateway computing devices, the delete message instructing the plurality of other gateway computing devices to remove the second object identifier and the second object location from respective caches.

9. The machine-readable storage medium of claim 8, wherein the instructions for updating and the instructions for transmitting the update message are triggered in response to one of:

storage of a first object corresponding to the first object identifier in the storage node, and

determining the first object location of the first object in the storage node during a lookup operation.

10. The machine-readable storage medium of claim 8, wherein the instructions for removing and the instructions for transmitting the delete message are triggered in response to removal of a second object corresponding to the second object identifier from the storage node.

11. A method for maintaining a local cache of object location information in a gateway computing device, the method comprising:

transmitting a first update message using a simple multicast transport protocol to a plurality of other gateway computing devices in response to adding a first object to the local cache, the first update message instructing the plurality of other gateway computing devices to add a first object identifier and a corresponding first object location to respective caches; and

transmitting a first delete message using a reliable multicast transport protocol to the plurality of other gateway computing devices in response to deletion of a second object from the local cache, the first delete message instructing the plurality of other gateway computing devices to remove a second object identifier and a corresponding second object location from the respective caches.

12. The method of claim 11, wherein the gateway computing device adds the first object to the local cache in response to one of:

storage of the first object in a storage node in communication with the gateway computing device, and

determining the first object location of the first object in the storage node during a lookup operation.

13. The method of claim 11, wherein the gateway computing device deletes the second object from the local cache in response to removal of the second object from a storage node in communication with the gateway computing device.

14. The method of claim 11, further comprising:

receiving a second update message transmitted by a respective gateway of the plurality of other gateway computing devices using the simple multicast transport protocol when a third object is stored in a cache of the respective gateway; and

adding a third object identifier and a third object location to the local cache in the gateway computing device in response to receiving the second update message.

15. The method of claim 11, further comprising:

receiving a second delete message transmitted by a storage node using the reliable multicast transport protocol when a third object is deleted from the storage node per expiration of an object retention policy for the third object; and

removing a third object identifier and a third object location from the local cache in the gateway computing device in response to receiving the second delete message.