Slipstream bandwidth management algorithm

• US 9,276,856 B2
• Filed: 10/10/2012
• Issued: 03/01/2016
• Est. Priority Date: 10/10/2011
• Status: Active Grant

• Current Assignee: Salesforce.com, Inc.
• Original Assignee: Salesforce.com, Inc.
• Inventors: Spencer, Barry
• Primary Examiner(s): Scott, Randy
• Application Number:
  US13/648,777
• Publication Number:
  US 20130091286A1
• Time in Patent Office: 1,238 Days
• Field of Search: 709/217, 709/226, 709/224, 709/232, 370/230, 370/252, 370/412
• US Class Current: 1/1
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/2416 Real-time traffic
• CPC Class Codes: H04L 47/25 with rate being modified by the source upon detecting a change of network conditions
• CPC Class Codes: H04L 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/365 Dynamic adaptation of the packet size
• CPC Class Codes: H04L 67/10 in which an application is distributed across nodes in the network software deployment G06F8/60; multiprogramming arrangements G06F9/46
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

In accordance with disclosed embodiments, there are provided methods, systems, and apparatuses for implementing a slipstream bandwidth management algorithm including, for example, means for executing an application a computing device, in which the application is to communicate with a remote computing device over a public Internet; means for approximating outgoing bandwidth for communications from the computing device to the remote computing device; means for approximating incoming bandwidth for communications received at the computing device from the remote computing device; means for allocating multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application based at least in part on the approximated outgoing bandwidth and based further on the approximated incoming bandwidth; and means for iteratively adjusting bandwidth communicated for the application between the computing device and the remote computing device based at least in part on latency between the computing device and the remote computing device. Other related embodiments are disclosed.

Claims

1. A method at a computing device, the method comprising:

executing an application at the computing device, the application to communicate with a remote computing device over a public Internet;

approximating outgoing bandwidth for communications from the computing device to the remote computing device;

approximating incoming bandwidth for communications received at the computing device from the remote computing device;

allocating multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application based at least in part on the approximated outgoing bandwidth and based further on the approximated incoming bandwidth; and

iteratively adjusting bandwidth communicated for the application between the computing device and the remote computing device based at least in part on latency between the computing device and the remote computing device, wherein iteratively adjusting bandwidth communicated for the application comprises applying an adjustment having the following operations;

sending a request packet from the computing device to a remote computing device;

calculating anticipated arrival time for a response packet from the remote computing device corresponding to the request packet sent;

receiving the response packet corresponding to the request packet sent;

determining whether the response packet arrived within a specified window of time; and

applying an adjustment to bandwidth communicated for the application based on whether the response packet arrived within the specified window of time, wherein applying an adjustment to the bandwidth communicated for the application based on whether the response packet arrived within the specified window of time comprises;

modifying a nominal packet size affecting the bandwidth communicated for the application.

2. The method of claim 1, wherein the application comprises one or more of the following application types:

a real-time communications application;

a low latency communications application;

a Voice over Internet Protocol (VoIP) application;

an audio streaming application;

a video streaming application;

a bi-directional audio streaming application;

a video streaming application;

a screen sharing application; and

a web-cam audio/video application.

3. The method of claim 1, wherein iteratively adjusting bandwidth communicated for the application comprises:

iteratively adjusting a nominal packet size for data packets communicated in support of the application between the computing device and the remote computing device based at least in part on latency between the computing device and the remote computing device.

4. The method of claim 1, wherein iteratively adjusting bandwidth communicated for the application comprises applying one or more of the following adjustments to the bandwidth communicated for the application:

(i) applying a slow adjustment operation;

(ii) applying an instantaneous adjustment operation; and

(iii) applying an Input/Output (I/O) cycle skipping adjustment operation.

5. The method of claim 1, wherein applying an adjustment to bandwidth communicated for the application based on whether the response packet arrived on time, comprises:

forcing a reduction to the bandwidth communicated for the application when the response packet is determined to have arrived after the anticipated arrival time.

6. The method of claim 5, wherein forcing the reduction to the bandwidth communicated for the application further comprises resetting a threshold delay for a next a reduction to the bandwidth communicated for the application, wherein the threshold delay prohibits further reduction to the bandwidth communicated until the threshold delay elapses.

7. The method of claim 1, wherein applying an adjustment to bandwidth communicated for the application based on whether the response packet arrived on time, comprises:

increasing the bandwidth communicated for the application when the response packet is determined to have arrived on time according to the anticipated arrival time.

8. The method of claim 7, wherein increasing the bandwidth communicated for the application when the response packet is determined to have arrived on time according to the anticipated arrival time, comprises:

calculating a confidence factor according to historic bandwidth increase successes; and

applying the confidence factor as a multiplier for increasing the bandwidth communicated for the application by at least a portion.

9. The method of claim 8, the confidence factor is affected by at least one of the following:

wherein the confidence factor increases based on a ratio of the historic bandwidth increase successes to historic bandwidth increase failures exceeding a threshold;

wherein the confidence factor decreases based on a ratio of the historic bandwidth increase failures exceeding historic bandwidth increase increases;

wherein the confidence factor increases based on the bandwidth communicated for the application being in effect for the application for an aggregate time period above a threshold time;

wherein the confidence factor decreases based on the bandwidth communicated for the application yet to have been successful at a rate above a present rate;

wherein the confidence factor increases based on a total quantity of historic bandwidth increase successes; and

wherein the confidence factor decreases based on a total quantity of historic bandwidth increase failures.

10. The method of claim 7, wherein applying the confidence factor as a multiplier for increasing the bandwidth communicated for the application by at least a portion, comprises:

applying the confidence factor as a multiplier to a nominal packet size affecting the bandwidth communicated for the application yielding a new nominal packet size; and

adopting the new nominal packet size causing the bandwidth communicated for the application to increase by at least a portion.

11. The method of claim 1, wherein iteratively adjusting bandwidth communicated for the application comprises applying an instantaneous adjustment having the following operations:

evaluating a backlog of request packets awaiting transmission from the computing device to the remote computing device;

determining whether the backlog of request packets exceeds a threshold;

applying a temporary reduction to packet sizes constituting the bandwidth communicated for the application until the backlog is determined to fall below a threshold; and

removing the temporary reduction.

12. The method of claim 11, wherein applying the temporary reduction to packet sizes constituting the bandwidth communicated for the application comprises:

retrieving a reduction value based on an extent the backlog is evaluated to exceed the threshold;

applying the reduction value to a nominal packet size to generate a modulated nominal packet size; and

adopting the modulated nominal packet size to effect an instantaneous reduction in the bandwidth communicated for the application.

13. The method of claim 12, wherein applying the reduction value to the nominal packet size to generate the modulated nominal packet size comprises:

temporarily adopting the modulated nominal packet size in place of the nominal packet size, the modulated nominal packet size affecting the bandwidth communicated for the application for the duration of its temporary adoption;

wherein outgoing bandwidth for the application constitutes sending request packets from the computing device to the remote computing device, the request packets having a request packet size based on the modulated nominal packet size; and

wherein incoming bandwidth for the application constitutes receiving response packets from the remote computing device responsive to request packets sent from the computing device, the response packets having a response packet size based on the modulated nominal packet size.

14. The method of claim 12, wherein retrieving the reduction value based on an extent the backlog is evaluated to exceed the threshold comprises one of:

(i) retrieving reduction values of 25%, 50%, 75%, or 100% based on whether the backlog exceeds one of a plurality of tiered thresholds, each corresponding to one of the reduction values;

(ii) retrieving reduction values of 25%, 50%, 75%, or 100% based on a quantity of request packets awaiting transmission from the computing device to the remote computing device presently queued;

or

(iii) retrieving reduction values of 25%, 50%, 75%, or 100% based on a ratio of queued request packets awaiting transmission to a quantity of previously transmitted request packets over a fixed period of time preceding the evaluation; and

wherein the method further comprises;

multiplying the reduction value retrieved against the nominal packet size to yield the modulated nominal packet size.

15. The method of claim 12, wherein removing the temporary reduction comprises:

iteratively evaluating whether the backlog remains above the threshold; and

reverting to the nominal packet size in effect before the instantaneous adjustment when the backlog is determined to have fallen below the threshold.

16. The method of claim 1, wherein iteratively adjusting bandwidth communicated for the application comprises applying an Input/Output (I/O) cycle skipping adjustment having the following operations:

evaluating a backlog of request packets awaiting transmission from the computing device to the remote computing device;

determining whether the backlog of request packets exceeds a threshold; and

skipping Input/Output (I/O) transmissions cycles of request packets from the computing device to the remote computing device effecting a reduction in the bandwidth communicated for the application until the backlog is determined to fall below a threshold.

17. The method of claim 16, wherein skipping the I/O transmissions cycles of request packets from the computing device to the remote computing device comprises:

retrieving a configured value for time between I/O transmission cycles;

modifying a quantity of cycles required between I/O cycles from a default of “

1”

to an integer greater than “

1;

”

multiplying the modified quantity of cycles required between I/O cycles by the configured time value for time between I/O transmission cycles to yield an I/O transmission cycle skipping time; and

triggering new I/O cycles for transmitting request packets from the computing device to the remote computing device according to the I/O transmission cycle skipping time, wherein the I/O transmission cycle skipping time is an integer multiple of the configured value for time between I/O transmission cycles.

18. The method of claim 16, wherein the method further comprises:

iteratively evaluating whether the backlog remains above the threshold; and

reverting from an I/O transmission cycle skipping time effecting the skipping of the I/O transmissions cycles of request packets to the configured value for time between I/O transmission cycles when the backlog is determined to have fallen below the threshold.

19. The method of claim 1, wherein allocating multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application comprises:

creating a plurality of TCP connections in a connection pool, the plurality of TCP connections dedicated exclusively to supporting the bandwidth communicated for the application and available to no other application executing at the computing device.

20. The method of claim 1, wherein allocating multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application comprises each of the multiple simultaneous TCP connections having one of the following enumerated states:

a closed state indicating the TCP connection to the remote computing device is currently closed;

a busy state indicating the TCP connection to the remote computing device is open, but is currently in use and awaiting a reply from the remote computing device; and

an available state indicating the TCP connection to the remote computing device is open, is not in use, and is immediately available for use.

21. The method of claim 20, wherein the method further comprises:

opening one or more of the simultaneous TCP connections when there are TCP connections in the closed state; and

dynamically allocating additional simultaneous TCP connections in support of the application when all of the multiple simultaneous TCP connections are in the busy state, and when none of the multiple simultaneous TCP connections are in the available state, and when none of the multiple simultaneous TCP connections are in the closed state.

22. The method of claim 21, wherein the method further comprises:

pre-allocating a minimum plurality of multiple simultaneous TCP connections in support of the application at an initiation phase according to a minimum simultaneous TCP connection threshold; and

wherein dynamically allocating additional simultaneous TCP connections in support of the application is restricted by a maximum simultaneous TCP connection threshold.

23. Non-transitory computer readable storage medium having instructions stored thereon that, when executed by a processor in a computing device, the instructions cause the computing device to perform operations comprising:

executing an application at the computing device, the application to communicate with a remote computing device over a public Internet;

approximating outgoing bandwidth for communications from the computing device to the remote computing device;

approximating incoming bandwidth for communications received at the computing device from the remote computing device;

allocating multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application based at least in part on the approximated outgoing bandwidth and based further on the approximated incoming bandwidth; and

iteratively adjusting bandwidth communicated for the application between the computing device and the remote computing device based at least in part on latency between the computing device and the remote computing device, wherein iteratively adjusting bandwidth communicated for the application comprises applying an adjustment having the following operations;

sending a request packet from the computing device to a remote computing device;

calculating anticipated arrival time for a response packet from the remote computing device corresponding to the request packet sent;

receiving the response packet corresponding to the request packet sent;

determining whether the response packet arrived within a specified window of time; and

applying an adjustment to bandwidth communicated for the application based on whether the response packet arrived within the specified window of time, wherein applying an adjustment to the bandwidth communicated for the application based on whether the response packet arrived within the specified window of time comprises;

modifying a nominal packet size affecting the bandwidth communicated for the application.

24. The non-transitory computer readable storage medium of claim 23, wherein iteratively adjusting bandwidth communicated for the application comprises applying one or more of the following adjustments to the bandwidth communicated for the application:

(i) applying a slow adjustment operation;

(ii) applying an instantaneous adjustment operation; and

(iii) applying an Input/Output (I/O) cycle skipping adjustment operation.

25. A computing device comprising:

a processor to execute an application, the application being operable to communicate with a remote computing device over a public Internet;

a regulator module to approximate outgoing bandwidth for communications from the computing device to the remote computing device;

the regulator module to approximate incoming bandwidth for communications received at the computing device from the remote computing device;

an Input/Output (I/O) pump to allocate multiple simultaneous Transmission Control Protocol (TCP) connections in support of the application based at least in part on the approximated outgoing bandwidth and based further on the approximated incoming bandwidth; and

the regulator module to iteratively adjust bandwidth communicated for the application between the computing device and the remote computing device based at least in part on latency between the computing device and the remote computing device, wherein iteratively adjusting bandwidth communicated for the application comprises applying an adjustment having the following operations;

sending a request packet from the computing device to a remote computing device;

calculating anticipated arrival time for a response packet from the remote computing device corresponding to the request packet sent;

receiving the response packet corresponding to the request packet sent;

determining whether the response packet arrived within a specified window of time; and

applying an adjustment to bandwidth communicated for the application based on whether the response packet arrived within the specified window of time, wherein applying an adjustment to the bandwidth communicated for the application based on whether the response packet arrived within the specified window of time comprises;

modifying a nominal packet size affecting the bandwidth communicated for the application.

26. The computing device of claim 25, wherein the I/O pump to allocate the multiple simultaneous TCP connections in support of the application comprises:

a connection pool of the I/O pump to maintain the multiple simultaneous TCP connections.

27. The computing device of claim 25, wherein:

a trigger of the I/O pump to iteratively trigger transmission of request packets from the computing device to the remote computing device according to a configured value for time between I/O transmission cycles.

28. The computing device of claim 25, further comprising:

an exchanger of the I/O pump to queue pending request packets awaiting transmission from the computing device to the remote computing device within a task queue; and

wherein the exchanger to further match pending request packets in the task queue to one of the multiple simultaneous TCP connections within a connection pool having an available state to transmit the pending request packets to the remote computing device via the multiple simultaneous TCP connections.

29. The computing device of claim 25, wherein the application comprises one or more of the following application types:

a real-time communications application;

a low latency communications application;

a Voice over Internet Protocol (VoIP) application;

an audio streaming application;

a video streaming application;

a bi-directional audio streaming application;

a video streaming application;

a screen sharing application; and

a web-cam audio/video application.