System and method for offline detection

• US 8,745,245 B1
• Filed: 09/15/2011
• Issued: 06/03/2014
• Est. Priority Date: 09/15/2011
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google Inc. (Alphabet Inc.)
• Inventors: Bullock, Nathan
• Primary Examiner(s): ZHANG, SHIRLEY X
• Application Number:
  US13/233,552
• Time in Patent Office: 992 Days
• Field of Search: 709/237, 709/233, 370/229, 370235-238
• US Class Current: 709/227
• CPC Class Codes: H04L 43/0811 by checking connectivity

Abstract

Systems and methods of offline detection are disclosed. The method includes generating a timeout value for offline detection at a plurality of clients. The method includes receiving a request from a client of the plurality of clients, sending an initial response to the client immediately after receiving the request from the client, sending one or more additional responses to the client, receiving timing information from the client, aggregating timing information received from the plurality of clients using a processor, and generating at least one timeout value based on the aggregated timing information.

Claims

1. A method comprising:

receiving a request from a client of a plurality of clients;

sending an initial response to the client immediately after receiving the request from the client;

sending one or more additional responses to the client;

receiving timing information from the client;

aggregating timing information received from the plurality of clients using a processor;

generating at least one timeout value based on the aggregated timing information;

sending a generated timeout value to the client; and

determining that the client is offline if the initial response is received by the client outside of a time period less than the generated timeout value, the time period beginning at a send time of the request.

2. The method of claim 1, further comprising:

sending at least one of the generated timeout values to at least some of the plurality of clients.

3. The method of claim 2, wherein the method is performed using a server that includes a web server and in the context of a web application implemented using the web server, the web application configured to utilize at least one of the sent generated timeout values to detect if the web application is in an online state or an offline state, the web application further configured to perform specific operations responsive to the current state.

4. The method of claim 1, wherein the timing information includes a network delay and at least one timing category, the timing categories including at least one of:

client device, client network address, or client location.

5. The method of claim 4, wherein generating the at least one timeout value comprises:

identifying at least one timing category value; and

generating a timeout value based on timing information associated with the at least one timing category value.

6. The method of claim 1, wherein generating a timeout value includes a statistical analysis of the aggregated timing information.

7. The method of claim 6, wherein generating a timeout value includes generating the timeout value using the statistical analysis and based on a confidence interval.

8. The method of claim 6, wherein generating the at least one timeout value comprises:

generating a timeout value for each of one or more timing categories included in the aggregated timing information.

9. The method of claim 1, wherein sending the initial response to the client immediately after receiving the request includes sending the initial response before performing any database queries responsive to the background request from the client.

10. A method of offline detection comprising:

collecting a dataset of timing information from a plurality of clients using a processor, the timing information including at least one network delay derived using at least one background request and at least one initial response, wherein at least some of the initial responses are sent immediately upon receipt of a background request;

generating at least one timeout value based on a statistical analysis of the dataset of timing information;

sending at least one of the generated timeout values to a client to facilitate offline detection by the client; and

determining that the client is offline if an initial response is received by the client outside of a time period less than at least one generated timeout value, the time period being a network delay and beginning at a time of at least one background request.

11. The method of claim 10, wherein sending the initial response to the client immediately upon receipt of a background request includes sending the initial response before performing any database queries responsive to the background request from the client.

12. The method of claim 10, wherein the statistical analysis includes a predetermined confidence interval.

13. The method of claim 10, wherein generating at least one timeout value comprises:

subdividing the dataset of timing information into category datasets based on timing categories included in the timing information; and

generating timeout values associated with the category datasets.

14. The method of claim 13, wherein sending at least one of the generated timeout values to the client comprises:

selecting a generated timeout value corresponding to a timing category associated with the client; and

sending the selected generated timeout value to the client.

15. A method of detecting an offline state of a client with respect to one or more servers, the method comprising:

receiving a document from the one or more servers;

sending a first background request to the one or more servers based on script included in the document;

receiving a first initial response from the one or more servers in response to the first background request;

calculating a network delay based on a difference in time between the sending of the first background request and the receipt of the first initial response;

sending the network delay to the one or more servers;

receiving one or more additional responses from the one or more servers in response to the first background request;

receiving a generated timeout value from the one or more servers; and

determining that the client is offline if an initial response is received from the one or more servers outside of a time period less than the generated timeout value, the time period beginning at a time of the first background request.

16. The method of claim 15, further comprising:

determining that the client is online if an initial response is received from the one or more servers within the time period; and

receiving one or more additional responses from the one or more servers if the client is online.

17. The method of claim 15, wherein the document is an HTML document, the receiving and sending is performed using the HTTP protocol, and the background requests and initial responses are performed using one or more XMLHTTPRequests.

18. The method of claim 15, wherein the document includes a generated timeout value, and the method further comprises:

sending a second background request to the one or more servers based on instructions included in the document; and

determining that the client is offline if a second initial response is not received within a time period after sending the second background request that is less than the generated timeout value.

19. The method of claim 18, wherein receiving the one or more additional responses is accomplished using an XHR streaming technique so that the initial response and one or more additional responses are received using a single HTTP connection and the initial response is received from the one or more servers before the additional response is received.

20. The method of claim 15, wherein the method is performed using a web browser.

21. The method of claim 15, wherein sending the network delay to the one or more servers comprises:

sending to the one or more servers timing information including a network delay calculated as the difference in time from sending the initial request to receiving the initial response.

22. A computing system for offline detection comprising:

one or more computing devices each having at least one memory and at least one processor, the one or more computing devices configured to execute instructions stored in the at least one memory to cause the computing system to perform functions comprising;

accessing a dataset of timing information collected by the computing system from a plurality of clients, the timing information including at least one network delay determined based on a difference in time between a send time of a background request and a receipt time of an initial response sent by a server immediately upon receipt of the background request,

processing at least one timeout value generated using a statistical analysis of the dataset of timing information,

storing the at least one timeout value in the at least one memory,

sending at least one of the generated timeout values to a client configured to use the at least one generated timeout value to detect an offline state, and

determining that the client is offline if the receipt time of the initial response is outside of a time period less than at least one generated timeout value, the time period being a network delay beginning at the send time of the background request.