SCALABLE QUEUES ON A SCALABLE STRUCTURED STORAGE SYSTEM

• US 20110099233A1
• Filed: 10/26/2009
• Published: 04/28/2011
• Est. Priority Date: 10/26/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: UDDARAJU, PADMANABHA CHAKRAVARTHY, CALDER, BRADLEY GENE, NILAKANTAN, NIRANJAN
• Granted Patent: US 8,266,290 B2
• Time in Patent Office: Days
• US Class Current: 709/206
• CPC Class Codes: G06F 9/546 Message passing systems or structures, e.g. queues

Abstract

A cloud computing platform contains a structured storage subsystem the provides scalable queues. The cloud computing platform monitors message throughput for the scalable queues and automatically increases or decreases subqueues that provide the operational functionality for each scalable queue. A visibility start time and cloud computing platform time are maintained for each message to provide an approximate first-in-first-out order for messages within each subqueue. A message in a subqueue may be available for processing when the current cloud computing time is greater than the visibility start of the message.

Claims

1. A computer-implemented method to manage a scalable queue, the method performed in a cloud computing platform and comprising:

receiving messages to add to a scalable queue, which are added to a plurality of subqueues;

ordering the messages in each subqueue;

and

obtaining one or more of the messages based on a time maintained by the cloud computing platform.

2. The computer-implemented method of claim 1, wherein adding new messages to a subqueue sets the visibility start times to a time maintained by the table servers operating within the cloud computing platform.

3. The computer-implemented method of claim 1, wherein dequeing a message updates the visibility start time of the obtained message is set to the current time maintained by the cloud computing platform plus a threshold time.

4. The computer-implemented method of claim 1, wherein dequeing a message does not update the visibility start time when a cloud application deletes the message.

5. The computer-implemented method of claim 3, further comprising sorting the messages in each subqueue based on visibility start time.

6. The computer-implemented method of claim 3, further comprising sorting the messages in each subqueue based priority.

7. The computer-implemented method of claim 3, wherein obtaining one or more of the messages based on a time maintained by the cloud computing platform further includes obtaining messages having visibility start time less than the time maintained by the table servers.

8. One or more computer-readable media storing instructions to perform a method in a cloud computing platform having a structured storage subsystem that provides scalable queues, the method comprising:

receiving a request to establish a scalable queue for an account registered with the cloud computing platform;

generating the scalable queue in the cloud computing platform in response to the request, wherein the scalable queue is a virtual queue comprising one or more subqueues; and

accessing the one or more subqueues to perform an operation on the scalable queue in the cloud computing platform.

9. The media of claim 8, wherein accessing a queue to perform an operation in the cloud computing platform includes at least one of the following:

identifying a number of subqueues associated with the virtual queue or determining a state associated with the virtual queue or a subset of the subqueues.

10. The media of claim 8, wherein the cloud computing platform includes a structured storage system that uses a durable distributed file system for storing its data.

11. The media of claim 8, further comprising:

monitoring, by the cloud computing platform, the performance of a scalable queue and its subqueues.

12. The media of claim 8, further comprising:

altering the number of subqueues available for the virtual queue when the existing subqueues cannot handle the load for the scalable queue.

13. The media of claim 8, further comprising:

increasing the number of subqueues automatically when requests to the subqueues start taking above a certain latency or the requests start timing out, or the requests are throttled by the table server.

14. The media of claim 8, further comprising:

decreasing the number of subqueues automatically when sizes for each subqueue goes below a size threshold and two or more subqueues are maintained by the cloud computing platform.

15. The media of claim 8, wherein the operation is one of:

put, get, delete, peek, or clear.

16. The media of claim 15, further comprising randomly selecting or selecting based on size of subqueue, by the cloud computing platform, a subqueue when performing a put, get, or peek operation.

17. The media of claim 16, wherein the state is one of all-operations-allowed, all-operations-except-put-allowed, and no-operations-allowed.

18. The media of claim 17, wherein the put operation is performed on subqueues in an all-operations-allowed state, and the cloud computing platform picks the subqueue based on size or randomly.

19. The media of claim 9, further comprising:

decreasing the number of subqueues automatically when latency goes below a threshold or throttling drops below a threshold for a pre-determined length of time.

20. A cloud computing platform that provides a scalable queue, the cloud computing platform comprising:

a front end server configured to receive application requests that create a scalable queue or add messages to an existing scalable queue;

a virtual queue manager configured to monitor the scalable queue, wherein the scalable queue increases or decreases number of subqueues based on the load to or number of messages in the scalable queue;

and

a storage system configured to provide tables that store messages for the scalable queue and to communicate with a table server when updating the tables based on requests received from the virtual queue manager or the front end server.