Technique for measuring round-trip latency to computing devices requiring no client-side proxy presence

• US 6,601,098 B1
• Filed: 06/07/1999
• Issued: 07/29/2003
• Est. Priority Date: 06/07/1999
• Status: Expired due to Term

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: International Business Machines Corporation
• Inventors: Topol, Brad B., Case, Ralph B.
• Primary Examiner(s): Jaroenchonwanit, Bunjob
• Application Number:
  US09/326,307
• Time in Patent Office: 1,513 Days
• Field of Search: 709/224, 709/225, 709/226, 370/257, 370/253, 370/254
• US Class Current: 709/224
• CPC Class Codes: H04L 43/0864 Round trip delays
• CPC Class Codes: H04L 43/50 Testing arrangements
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/30 Managing network names, e.g. use of aliases or nicknames name-to-address mapping H04L61/45
• CPC Class Codes: H04L 67/02 based on web technology, e.g. hypertext transfer protocol [HTTP]
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]

Abstract

A method, system, and computer-readable code for measuring network latency between a client computer and a server machine without requiring any additional software on the client. Network latency is a measurement that reflects the network round trip delay between a client machine and a server machine. The present invention defines a novel technique for gathering latency information. This information may be used in a variety of ways (such as making policy decisions that may limit the amount of data sent over a communications path due to detection of high latency in the network).

Claims

1. In a computing environment connected to a network, computer readable code stored on a storage medium readable by a computer system in said environment for measuring round-trip latency between a client and a server without requiring a client-side proxy presence, comprising:

computer readable code means for receiving, at said server from said client, a first client request for a first Uniform Resource Locator (URL);

computer readable code means for determining, responsive to receiving said first client request, that said round-trip latency between said client and said server is to be measured; and

computer readable code means for measuring said round-trip latency, further comprising;

computer readable code means for storing a first time at which said first client request was received;

computer readable code means for responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

computer readable code means for receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

computer readable code means for computing a difference between said second time and said first time, wherein said difference represents said round-trip latency; and

computer readable code means for sending to said client, responsive to receiving said second client request, information associated with said first URL.

2. Computer readable code for measuring round-trip latency according to claim 1, wherein said redirection response uses a page temporarily moved status code.

3. Computer readable code for measuring round-trip latency according to claim 1, wherein said redirection response uses a page permanently moved status code.

4. Computer readable code for measuring round-trip latency according to claim 1, wherein said first URL is a configurable parameter defined to trigger said computer readable code means for determining.

5. Computer readable code for measuring round-trip latency according to claim 1, wherein said server is a server-side proxy server, and further comprising:

computer readable code means for forwarding said first client request from said proxy server to a target server identified in said first client request; and

computer readable code means for receiving, at said proxy server, a response to said forwarded request from said target server, wherein said response comprises said information associated with said first URL.

6. Computer readable code for measuring round-trip latency according to claim 1, wherein said computer readable code means for determining is triggered using a counter of requests received.

7. In a computing environment connected to a network, computer readable code stored on a storage medium readable by a computer system in said environment for measuring round-trip latency between a client and a server without requiring a client-side proxy presence, comprising:

computer readable code means for receiving, at said server from said client, a first client request for a first Uniform Resource Locator (URL);

computer readable code means for determining, responsive to receiving said first client request, that said round-trip latency between said client and said server is to be measured; and

computer readable code means for measuring said round-trip latency, further comprising;

computer readable code means for storing a first time at which said first client request was received;

computer readable code means for responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

computer readable code means for receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

computer readable code means for storing said second time for subsequent computation of said round-trip latency, wherein said round-trip latency is a difference between said second time and said first time; and

computer readable code means for sending to said client, responsive to receiving said second client request, information associated with said first URL.

8. A system for measuring round-trip latency between a client and a server without requiring a client-side proxy presence in a computing environment connected to a network, comprising:

means for receiving, at said server from said client, a first client request for a first Uniform Resource Locator (URL);

means for determining, responsive to receiving said first client request, that said roundtrip latency between said client and said server is to be measured; and

means for measuring said round-trip latency, further comprising;

means for storing a first time at which said first client request was received;

means for responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

means for receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

means for computing a difference between said second time and said first time, wherein said difference represents said round-trip latency; and

means for sending to said client, responsive to receiving said second client request, information associated with said first URL.

9. The system for measuring round-trip latency according to claim 8, wherein said redirection response uses a page temporarily moved status code.

10. The system for measuring round-trip latency according to claim 8, wherein said redirection response uses a page permanently moved status code.

11. The system for measuring round-trip latency according to claim 8, wherein said first URL is a configurable parameter defined to trigger said means for determining.

12. The system for measuring round-trip latency according to claim 8, wherein said server is a server-side proxy server, and further comprising:

means for forwarding said first client request to from said proxy to a target server identified in said first client request; and

means for receiving, at said proxy server, a response to said forwarded request from said target server, wherein said response comprises said information associated with said first URL.

13. The system for measuring round-trip latency according to claim 8, wherein said means for determining is triggered using a counter of requests received.

14. A system for measuring round-trip latency between a client and a server without requiring a client-side proxy presence in a computing environment connected to a network, comprising:

means for receiving, at said server from said client, a first client request for a first Uniform Resource Locator (URL);

means for determining, responsive to receiving said first client request, that said round-trip latency between said client and said server is to be measured; and

means for measuring said round-trip latency, further comprising;

means for storing a first time at which said first client request was received;

means for responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

means for receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

means for storing said second time for subsequent computation of said round-trip latency, wherein said round-trip latency is a difference between said second time and said first time; and

means for sending to said client, responsive to receiving said second client request, information associated with said first URL.

15. A method for measuring round-trip latency between a client and a server without requiring a client-side proxy presence in a computing environment connected to a network, comprising the steps of:

receiving, at said server from said client, a first client request for a first Uniform Resource Locator (URL);

determining, responsive to receiving said first client request, that said round-trip latency between said client and said server is to be measured; and

measuring said round-trip latency, further comprising the steps of;

storing a first time at which said first client request was received;

responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

computing a difference between said second time and said first time, wherein said difference represents said round-trip latency; and

sending, responsive to receiving said second client request, information associated with said first URL.

16. The method for measuring round-trip latency according to claim 15, wherein said redirection response uses a page temporarily moved status code.

17. The method for measuring round-trip latency according to claim 15, wherein said redirection response uses a page permanently moved status code.

18. The method for measuring round-trip latency according to claim 15, wherein said first URL is a configurable parameter defined to trigger said determining step.

19. The method for measuring round-trip latency according to claim 15, wherein said server is a server-side proxy server, and further comprising the steps of:

forwarding said first client request from said proxy server to a target server identified in said first client request; and

receiving, at said proxy server, a response to said forwarded request from said target server, wherein said response comprises said information associated with said first URL.

20. The method for measuring round-trip latency according to claim 15, wherein said determining step is triggered using a counter of requests received.

21. The method for measuring round-trip latency according to claim 15, wherein said determining step is triggered using a time of day.

22. The method for measuring round-trip latency according to claim 15, wherein said determining step is triggered using a source address in said first client request.

23. A method for measuring round-trip latency between a client and a server without requiring a client-side proxy presence in a computing environment connected to a network, comprising the steps of:

receiving, at said server from said client, a first client request for a first Uniform Resource

determining, responsive to receiving said first client request, that said round-trip latency between said client and said server is to be measured; and

measuring said round-trip latency, further comprising the steps of;

storing a first time at which said first client request was received;

responding to said first client request with a redirection response, wherein said redirection response specifies a second URL;

receiving, from said client, a second client request for said second URL, wherein said second client request is received at a second time;

storing said second time for subsequent computation of said round-trip latency, wherein said round-trip latency is a difference between said second time and said first time; and

sending to said client, responsive to receiving said second client request, information associated with said first URL.