Maintaining caches of object location information in gateway computing devices using multicast messages

• US 9,094,466 B2
• Filed: 04/07/2011
• Issued: 07/28/2015
• Est. Priority Date: 04/07/2011
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Alam, Shahid
• Primary Examiner(s): Yen, Syling
• Application Number:
  US13/082,223
• Publication Number:
  US 20120259821A1
• Time in Patent Office: 1,573 Days
• Field of Search: 707/610, 707/611, 707/613, 707/617, 707/620, 707/624, 707/626, 707/634, 707/636, 707/640, 707/661, 707/674, 707/693, 707/999.204
• US Class Current: 1/1
• 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 of objects stored in a storage system; and

a processor to;

receive a request to store a first object in the storage system;

forward the request to the storage system to store the first object;

in response to the first object being stored in the storage system, create a new entry in the cache, wherein the new entry includes an object identifier, a timestamp of the new entry, and a storage location of the first object;

in response to the creation of the new entry in the cache, transmit a cache update message to other gateway computing devices, wherein the cache update message includes information of the new entry and instructions to instruct the other gateway computing devices to add the information of the new entry in respective caches of the other gateway computing devices;

receive a request to access a second object stored in the storage system,

execute a lookup to determine a storage location of the second object in the storage system when a corresponding second object identifier is not located in the cache,

update the cache to include an entry of the second object identifier, a timestamp of the entry, and the storage location of the second object based on the lookup, and

transmit a second update message to the other gateway computing devices, the second update message instructing the other gateway computing devices to add the second object identifier and the storage location of the second object to the respective caches in the other gateway computing devices.

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

receive a delete request including a third object identifier of a third object to be deleted from a storage node in the storage system,

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

remove an entry including the third object identifier and a corresponding third storage location of the third object from the cache, and

transmit a delete message to the other gateway computing devices, the delete message instructing the other gateway computing devices to remove the third object identifier and the third storage location of the third object from the respective caches of the other gateway computing devices.

3. The gateway computing device of claim 1, wherein the new entry in the cache further includes information indicating a time duration that the new entry is to be maintained in the cache according to a retention policy, and wherein the processor is further to:

remove the new entry from the cache at an end of the time duration in accordance with the retention policy.

4. The gateway computing device of claim 2, wherein:

the processor is to receive the delete request upon deletion of the third object from the storage system based on an expiration of a retention policy for the third object.

5. 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.

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

the first gateway computing device is a Simple Mail Transfer Protocol (SMTP) portal.

7. A non-transitory 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 non-transitory machine-readable storage medium comprising instructions to:

receive a request to store a first object in a storage system;

forward the request to the storage system to store the first object;

in response to the first object being stored in the storage system, create a new entry in the cache, wherein the new entry includes an object identifier, a timestamp of the new entry, and a storage location of the first object;

in response to the creation of the new entry in the cache, transmit a cache update message to other gateway computing devices, wherein the cache update message includes information of the new entry and instructions to instruct the other gateway computing devices to add the information of the new entry in respective caches of the other gateway computing devices;

receive a request to access a second object stored in the storage system;

execute a lookup to determine a storage location of the second object in the storage system when a corresponding second object identifier is not located in the cache;

update the cache to include an entry of the second object identifier, a timestamp of the entry, and the storage location of the second object based on the lookup; and

transmit a second update message to instruct the other gateway computing devices to add the second object identifier and the storage location of the second object to the respective caches in the other gateway computing devices.

8. The non-transitory machine-readable storage medium of claim 7, further comprising instructions to remove, from the cache, an entry associated with a third object in response to a removal of the third object from the storage system.

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

receiving a request to store a first object in a storage system;

forwarding, by a processor of the gateway computing device, the request to the storage system to store the first object;

creating, by the processor, a new entry in the local cache, wherein the new entry includes an object identifier, a timestamp of the new entry, and a storage location of the first object;

in response to the creation of the new entry in the local cache, transmitting a cache update message to other gateway computing devices, wherein the cache update message includes information of the new entry and instructions to instruct the other gateway computing devices to add the information of the new entry in respective caches of the other gateway computing devices;

receiving a request to access a second object stored in the storage system;

executing a lookup to determine a storage location of the second object in the storage system when a corresponding second object identifier is not located in the local cache;

updating the local cache to include an entry of the second object identifier, a timestamp of the entry, and the storage location of the second object based on the lookup; and

transmitting a second update message to instruct the other gateway computing devices to add the second object identifier and the storage location of the second object to the respective caches in the other gateway computing devices.

10. The method of claim 9, further comprising:

deleting an entry associated with a third object from the local cache in response to removal of the third object from the storage system in communication with the gateway computing device.

11. The method of claim 9, further comprising:

receiving an update message transmitted by one of the other gateway computing devices when an entry associated with a third object is stored in a cache of the other gateway computing device; and

adding a third object identifier identifying the third object and a third object location identifying a location in the storage system where the third object is stored, to the local cache in the gateway computing device in response to receiving the second update message.

12. The method of claim 9, further comprising:

receiving a delete message transmitted by a storage node of the storage system when a third object is deleted from the storage node per an expiration of an object retention policy for the third object; and

removing an entry including a third object identifier identifying the third object and a third object location identifying a location in the storage system where the third object is stored, from the local cache in the gateway computing device in response to receiving the delete message.