Automatic relaxing and revising of target server specifications for enhanced requests servicing

• US 7,694,014 B2
• Filed: 07/30/2007
• Issued: 04/06/2010
• Est. Priority Date: 07/30/2007
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, Hao, Shen, Jinmei
• Primary Examiner(s): VU, VIET DUY
• Application Number:
  US11/830,292
• Publication Number:
  US 20090037599A1
• Time in Patent Office: 981 Days
• Field of Search: 709/220, 709/223, 709/224, 709/225, 709/230, 709/238, 709/250
• US Class Current: 709/238
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context

Abstract

A method, system and computer program product for dynamically modifying target server specifications to improve the success rate of client requests in a data network. A client'"'"'s initial request is transmitted by a client router to a dynamically updating target server, based on information in a client'"'"'s routing table. A Dynamic Server Specifications (DSS) utility automatically revises one or more target specifications of a client'"'"'s request that is not initially fulfilled. The DSS utility then initiates the transmission of the modified request to an alternate server. If the request to the alternate server is also not fulfilled, the DSS utility may further modify the request to target an arbitrary server in order to download a current routing table. When the client receives a current routing table, the initial request is revised based on the current routing information, with full constraints re-established, and forwarded to the relevant target server.

Claims

1. In a device having mechanisms for communicating with a plurality of application servers via a network, a method comprising:

transmitting an initial request via a client router to a first target server, which is identified based on information in a client routing table of the client router;

when the initial request is not acknowledged by the first target server;

dynamically modifying a target server specification of a next request by relaxing one or more constraints, which were included in the first request, within the next request; and

issuing the next request with the relaxed constraints to locate an alternate target server.

2. The method of claim 1, wherein said transmitting further comprises:

selecting the first target server identified by information from the client routing table;

appending a timestamp of the client routing table to the client request;

transmitting the client request with the timestamp to the first target server;

tracking a timeout period within which a response is expected from a target server to which a client request is transmitted; and

initiating the dynamic modifying when no response is received from the target server before the timeout period expires.

3. The method of claim 2, wherein, when a response is received from one of the first target server and the alternate server, said method comprises:

replacing the client routing table with a current routing table that has a more current timestamp than the client routing table, wherein the current routing table is automatically provided from the target server in response to receipt at the target server of a the client request with a timestamp that is earlier than a current timestamp of the current routing table of the target server;

selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

forwarding the new client request to the correct target server identified within the current routing table.

4. The method of claim 1, wherein said modifying further comprises:

forwarding the next client request with relaxed constraints to an alternate server; and

when the forwarded request does not reach the alternate server;

further revising server specifications of a subsequent request by relaxing one or more of the constraints to enable contact with an arbitrary server; and

transmitting the subsequent client request to the arbitrary server.

5. The method of claim 4, further comprising:

appending a pre-defined low timestamp value to the subsequent client request, which indicates to the arbitrary server that the arbitrary server should immediately forward to the requesting client router a current routing table, wherein the appending is initiated when there is insufficient information in the client routing table for a client request to be properly routed; and

when a response is received from the arbitrary server;

replacing the client routing table with the current routing table when the current routing table is provided in response to the client request;

selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

forwarding the new client request to the correct target server.

6. The method of claim 1, wherein when one of (a) the client request does not receive a response from any arbitrary server after relaxing all levels of constraints and (b) required metrics associated with the client requests are not met, said method further comprising at least one of:

logging all of conditions and notify a system administrator to pay attention on the system and change certain constraints and reset client parameters to enable communication with target servers on the network; and

signaling an automatic service deployment controller to adjust the server cluster deployment configuration automatically.

7. The method of claim 1, wherein when the client router provides server functionality, said method further comprises:

responsive to a receipt of a network-transmitted client request, checking a timestamp appended to the client request representing the timestamp of the client routing table of an originating client from which the client request originated;

downloading a current routing table to the originating client to update the client routing table of the originating client when the timestamp comprises one of the following qualities;

(a) an earlier timestamp than the timestamp of the current routing table;

(b) a timestamp that is not equivalent to the timestamp of the target server; and

(c) a timestamp with a pre-defined negative value indicating a request to automatically download a new routing table to the originating client; and

when the timestamps of the client and the target server are equivalent, granting access to the originating client in response to receipt of the client request from the originating client.

8. A router for use in communicating between a client and one or more target servers within a network, said router comprising:

means for communicatively connecting to the client and the one or more target servers;

logic for transmitting an initial request via a client router to a first target server, which is identified based on information in a client routing table of the client router;

when the initial request is not acknowledged by the first target server;

logic for dynamically modifying a target server specification of a next request by relaxing one or more constraints, which were included in the first request, within the next request; and

logic for issuing the next request with the relaxed constraints to locate an alternate target server.

9. The router of claim 8, wherein said logic for transmitting further comprises:

logic for selecting the first target server identified by information from the client routing table;

logic for appending a timestamp of the client routing table to the client request;

logic for transmitting the client request with the timestamp to the first target server;

logic for tracking a timeout period within which a response is expected from a target server to which a client request is transmitted; and

logic for initiating the dynamic modifying when no response is received from the target server before the timeout period expires.

10. The router of claim 9, wherein, when a response is received from one of the first target server and the alternate server, said router comprises:

logic for replacing the client routing table with a current routing table that has a more current timestamp than the client routing table, wherein the current routing table is automatically provided from the target server in response to receipt at the target server of a the client request with a timestamp that is earlier than a current timestamp of the current routing table of the target server;

logic for selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

logic for forwarding the new client request to the correct target server identified within the current routing table.

11. The router of claim 8, wherein said logic for modifying further comprises:

logic for forwarding the next client request with relaxed constraints to an alternate server; and

when the forwarded request does not reach the alternate server;

logic for further revising server specifications of a subsequent request by relaxing one or more of the constraints to enable contact with an arbitrary server; and

logic for transmitting the subsequent client request to the arbitrary server.

12. The router of claim 11, further comprising:

logic for appending a pre-defined low timestamp value to the subsequent client request, which indicates to the arbitrary server that the arbitrary server should immediately forward to the requesting client router a current routing table, wherein the appending is initiated when there is insufficient information in the client routing table for a client request to be properly routed; and

when a response is received from the arbitrary server;

logic for replacing the client routing table with the current routing table when the current routing table is provided in response to the client request;

logic for selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

logic for forwarding the new client request to the correct target server.

13. The router of claim 8, wherein when one of (a) the client request does not receive a response from any arbitrary server after relaxing all levels of constraints and (b) required metrics associated with the client requests are not met, said logic further comprising at least one of:

logic for logging all of conditions and notify a system administrator to pay attention on the system and change certain constraints and reset client parameters to enable communication with target servers on the network; and

logic for signaling an automatic service deployment controller to adjust the server cluster deployment configuration automatically.

14. The router of claim 8, wherein when the client router provides server functionality, said router further comprises:

logic for responsive to a receipt of a network-transmitted client request, checking a timestamp appended to the client request representing the timestamp of the client routing table of an originating client from which the client request originated;

logic for downloading a current routing table to the originating client to update the client routing table of the originating client when the timestamp comprises one of the following qualities;

(d) an earlier timestamp than the timestamp of the current routing table;

(e) a timestamp that is not equivalent to the timestamp of the target server; and

(f) a timestamp with a pre-defined negative value indicating a request to automatically download a new routing table to the originating client; and

when the timestamps of the client and the target server are equivalent, logic for granting access to the originating client in response to receipt of the client request from the originating client.

15. A computer program product comprising a computer readable medium having program code thereon, wherein the program code executes to perform the functions of:

transmitting an initial request via a client router to a first target server, which is identified based on information in a client routing table of the client router;

when the initial request is not acknowledged by the first target server;

dynamically modifying a target server specification of a next request by relaxing one or more constraints, which were included in the first request, within the next request; and

issuing the next request with the relaxed constraints to locate an alternate target server.

16. The computer program product of claim 15, wherein said program code for transmitting further comprises code for:

selecting the first target server identified by information from the client routing table;

appending a timestamp of the client routing table to the client request;

transmitting the client request with the timestamp to the first target server;

tracking a timeout period within which a response is expected from a target server to which a client request is transmitted; and

initiating the dynamic modifying when no response is received from the target server before the timeout period expires.

17. The computer program product of claim 16, wherein, when a response is received from one of the first target server and the alternate server, said program code comprises code for:

replacing the client routing table with a current routing table that has a more current timestamp than the client routing table, wherein the current routing table is automatically provided from the target server in response to receipt at the target server of a the client request with a timestamp that is earlier than a current timestamp of the current routing table of the target server;

selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

forwarding the new client request to the correct target server identified within the current routing table.

18. The computer program product of claim 15, wherein said program code for modifying further comprises code for:

forwarding the next client request with relaxed constraints to an alternate server;

when the forwarded request does not reach the alternate server;

further revising server specifications of a subsequent request by relaxing one or more of the constraints to enable contact with an arbitrary server; and

transmitting the subsequent client request to the arbitrary server; and

when one of (a) the client request does not receive a response from any arbitrary server after relaxing all levels of constraints and (b) required metrics associated with the client requests are not met, said program code further comprising code for performing at least one of;

logging all of conditions and notify a system administrator to pay attention on the system and change certain constraints and reset client parameters to enable communication with target servers on the network; and

signaling an automatic service deployment controller to adjust the server cluster deployment configuration automatically.

19. The computer program product of claim 18, further comprising program code for:

appending a pre-defined low timestamp value to the subsequent client request, which indicates to the arbitrary server that the arbitrary server should immediately forward to the requesting client router a current routing table, wherein the appending is initiated when there is insufficient information in the client routing table for a client request to be properly routed; and

when a response is received from the arbitrary server;

replacing the client routing table with the current routing table when the current routing table is provided in response to the client request;

selecting a correct target server from the current routing table and generating a new client request including the correct target server and full constraints; and

forwarding the new client request to the correct target server.

20. The computer program product of claim 15, wherein when the client router provides server functionality, said program code further comprises code for:

responsive to a receipt of a network-transmitted client request, checking a timestamp appended to the client request representing the timestamp of the client routing table of an originating client from which the client request originated;

downloading a current routing table to the originating client to update the client routing table of the originating client when the timestamp comprises one of the following qualities;

(g) an earlier timestamp than the timestamp of the current routing table;

(h) a timestamp that is not equivalent to the timestamp of the target server; and

(i) a timestamp with a pre-defined negative value indicating a request to automatically download a new routing table to the originating client; and

when the timestamps of the client and the target server are equivalent, granting access to the originating client in response to receipt of the client request from the originating client.