Efficient synchronization of agents starting a task where the agents poll a server to learn the task start time

• US 20080294769A1
• Filed: 05/25/2007
• Published: 11/27/2008
• Est. Priority Date: 05/25/2007
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Kosuda, Masahiko, Doi, Kenshi
• Application Number:
  US11/754,179
• Publication Number:
  US 20080294769A1
• Time in Patent Office: Days
• US Class Current: 709/224
• CPC Class Codes: G06F 2209/541 Client-server
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores
• CPC Class Codes: G06F 9/54 Interprogram communication

Abstract

A server sets a task start time equal to a next polling time by a last agent that has most recently polled the server. In response to each of a number of agents, including the last agent, polling the server, the server provides the task start time. At each agent, a task is started at the task start time, such that all the agents start the task at a same time. As such, all the agents except for the last agent have to wait for the task start time to start the task after polling the server, whereas the last agent starts the task immediately after polling the server. The server may also determine a polling interval time based on a number of the agents that have polled the server, where the polling interval time indicates how long each agent waits between successive pollings of the servers.

Claims

1. A computerized method comprising:

setting a task start time by a server, the task start time set equal to a next polling time by a last agent that has most recently polled the server, the next polling time being a time at which the last agent is expected to again poll the server;

in response to each of a plurality of agents, including the last agent, polling the server, the server responding with the task start time; and

,

at each of the plurality of agents, starting a task at the task start time, such that all of the plurality of agents start the task at a same time,

wherein all of the plurality of agents except for the last agent have to wait for the task start time to start the task after polling the server, and the last agent starts the task immediately after polling the server.

2. The method of claim 1, wherein the method is performed responsive to an instruction to have the plurality of agents start the task.

3. The method of claim 1, further comprising, initially:

each of the plurality of agents polling the server, including providing an identifier that uniquely identifies the agent compared to other agents;

the server recording the identifier of each agent polling the server so that the server is able to determine a number of the agents that have polled the server;

the server determining a polling interval time based on the number of the agents that have polled the server, the polling interval time indicating how long each agent waits between successive pollings of the server; and

,

in response to each of the plurality of agents polling the server, the server responding with the polling interval time that has been determined, such that each agent waits to again poll the server until the polling interval time has elapsed.

4. The method of claim 3, wherein the task start time is set equal to the next polling time by the last agent that has most recently polled the server by adding the polling interval time to a most recent time that the last agent has polled the server.

5. The method of claim 3, wherein the polling interval time is sent from the server to each agent as a negative number to distinguish the polling interval time from the task start time, the task start time sent from the server to each agent as a positive number, each agent taking an absolute value of the negative number to determine the polling interval time.

6. The method of claim 3, further comprising the server determining the number of the agents that have polled the server by counting a number of unique identifiers that have been received from the plurality of agents polling the server and recorded by the server during a predetermined period of time in which it is at least substantially guaranteed that each agent has polled the server at least once.

7. The method of claim 3, wherein the server determining the polling interval time based on the number of the agents that have polled the server by multiplying the number of the agents that have polled the server by a base polling time.

8. The method of claim 1, wherein the server is a hypertext transport protocol (HTTP) server implemented at least in hardware.

9. The method of claim 8, wherein each agent is a web browsing computer program.

10. The method of claim 1, wherein each agent is a computer program running on a computing device implemented at least in hardware.

11. The method of claim 10, wherein one of:

the plurality of agents are running on a same computing device; and

,

at least two of the agents are running on different computing devices.

12. The method of claim 1, wherein the server and the agents are communicatively connected to one another over a network.

13. A computerized system comprising:

one or more computing devices, a plurality of agents running on the computing devices;

a server implemented at least in hardware and communicatively connected with the plurality of agents, the server setting a task start time equal to a next polling time by a last agent of the plurality of agents, the last agent having most recently polled the server, the next polling time being a time at which the last agent is expected to again poll the server,

such that in response to each of the plurality of agents polling the server, the server responds with the task start time, and in response each of the plurality of agents starts a task at the task start time, so that all of the plurality of agents start the task at a same time,

wherein all of the plurality of agents except for the last agent have to wait for the task start time to start the task after polling the server, and the last agent starts the task immediately after polling the server.

14. The system of claim 13, wherein the server sets the task start time in response to an instruction to the server to have the plurality of agents start the task.

15. The system of claim 13, wherein each of the plurality of agents provides, when polling the server, an identifier that uniquely identifies the agent compared to other agents, the server record the identifier of each agent polling the server within a storage of the server so that the server is able to determine a number of the agents that have polled the server.

16. The system of claim 15, wherein the server is to determine a polling interval time based on the number of agents that have polled the server, the polling interval time indicating how long each agent waits between successive pollings of the server,

the server, response to each agent polling the server, transmitting the polling interval time that has been determined, such that each agent waits to again poll the server until the polling interval time has elapsed.

17. The system of claim 16, wherein the polling interval time is sent from the server to each agent as a negative number to distinguish the polling interval time from the task start time, the task start time sent from the server to each agent as a positive number, each agent taking an absolute value of the negative number to determine the polling interval time.

18. The system of claim 13, wherein the server is a hypertext transport protocol (HTTP) server implemented at least in hardware.

19. The system of claim 18, wherein each agent is a web browsing computer program.

20. A computer-readable medium having one or more computer programs stored thereon and executable by a server to perform a method comprising:

in response to each of a plurality of agents polling the server, including providing an identifier that uniquely identifies the agent compared to other agents,

the server recording the identifier of each agent polling the server so that the server is able to determine a number of the agents that have polled the server;

the server determining a polling interval time based on the number of the agents that have polled the server, the polling interval time indicating how long each agent waits between successive pollings of the server;

in response to each of the plurality of agents polling the server,

the server responding with the polling interval time that has been determined, such that each agent waits to again poll the server until the polling interval time has elapsed;

the server setting a task start time equal to a next polling time by a last agent of the plurality of agents that has most recently polled the server, the next polling time being a time at which the last agent is expected to again poll the server; and

,

in response to each of the plurality of agents, including the last agent, polling the server, the server responding with the task start time,

such that each of the plurality of agents starts a task at the task start time so that all of the plurality of agents start the task at a same time,

wherein all of the plurality of agents except for the last agent have to wait for the task start time to start the task after polling the server, and the last agent starts the task immediately after polling the server.