Method, system and machine accessible medium of a reconnect mechanism in a distributed system (cluster-wide reconnect mechanism)

• US 7,937,611 B2
• Filed: 12/28/2007
• Issued: 05/03/2011
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: SAP SE
• Original Assignee: SAP AG (SAP SE)
• Inventors: Matov, Peter K., Tankov, Nikolai D., Gatev, Andrei A.
• Primary Examiner(s): Baderman; Scott T
• Assistant Examiner(s): KO, CHAE M
• Application Number:
  US11/966,846
• Publication Number:
  US 20090172463A1
• Time in Patent Office: 1,222 Days
• Field of Search: 714/4, 714/43
• US Class Current: N/A
• CPC Class Codes: G06F 11/1443 Transmit or communication errors

Abstract

A method, system and machine accessible medium for validating a plurality of connections to a backend in a distributed system. A connection request requiring access to a backend is processed at a first node of a distributed system. The access to the backend enabled through a connection from a plurality of connections on the first node. The plurality of connections on the first node is validated in response to a connection request failure. A plurality of connections on a second node is validated in response to the connection request failure.

Claims

1. A method for validating access to a backend system in a distributed computer system comprising:

maintaining a first pool of reusable connections in a first server of the distributed computer system, wherein each connection from the first pool of reusable connections provides access to the backend system linked to the distributed computer system via a network for at least one application executed at the first server;

generating a connection request by an application executed at the first server for accessing the backend system;

detecting failure of the connection request due to a connection error at the first server of the distributed computer system, wherein the error indicates an invalid connection in the first pool of reusable connections;

removing a set of invalid connections from the first pool of reusable connections responsive to the connection error; and

triggering a validation of a second pool of reusable connections at a second server of the distributed computer system responsive to the connection error, wherein each connection from the second pool of reusable connections provides access to the backend system for at least one application executed at the second server.

2. The method of claim 1 wherein generating the connection request by the application executed at the first server comprises:

receiving an application request from a user at the first server executing the application, wherein the application accesses the backend system to process the application request; and

routing an access to the backend system through a connection from the first pool of reusable connections providing access to the backend system at the first server.

3. The method of claim 1, wherein removing the set of invalid connections from the first pool of reusable connections at the first server comprises:

identifying at least one invalid connection from the first pool of reusable connections by calling a connectivity framework method for connections validity check in the first server, wherein the method for connections validity check receives a set of connections to be validated from the first pool of reusable connections and returns the at least one invalid connection; and

destroying the identified at least one invalid connection by calling a resource cleanup method in the first server.

4. The method of claim 1 further comprising:

creating a new connection in the first pool of reusable connections providing access to the backend system responsive to the connection error.

5. The method of claim 1, wherein triggering the validation of the second pool of reusable connections at the second server comprises:

sending a notification message to the second server using a notification mechanism provided in the distributed computer system, the message indicative of the connection error detected at the first server.

6. The method of claim 1, wherein triggering the validation of the second pool of reusable connections at the second server comprises:

sending a notification message to the second server using a notification mechanism provided in the distributed computer system when there is no valid connection in the first pool of reusable connections providing access to the backend system on the first server.

7. The method of claim 1 further comprising:

receiving a notification message from a third server of the distributed computer system, the message indicative for a connection error to the backend system for an application executed at the third server; and

removing at least one invalid connection from the first pool of reusable connections responsive to the notification message.

8. The method of claim 1 further comprising:

generating a new connection request by the application executed at the first server for accessing the backend system when the validation of the second pool of reusable connections has been triggered.

9. A system for validating access to a backend system comprising:

a memory to store program code; and

a processor coupled with the memory and configured to execute the program code stored in the memory to

maintain a first pool of reusable connections in the first server node,

wherein each connection of the first pool of reusable connections provides access to the backend system for at least one application executed at the first server node,

generate a connection request by an application executed at the first server node for accessing the backend system;

detect failure of the connection request due to a connection error indicating an invalid reusable connection in the first pool of reusable connections,

validate a plurality of connections of the first pool of reusable connections responsive to the connection error, and

trigger a validation of a second pool of reusable connections at a second server node of the distributed computer system responsive to the connection error, wherein each connection from the second pool of reusable connections provides access to the backend system for at least one application executed at the second server node.

10. The system of claim 9, wherein the memory further comprises:

a connection handler program code configured to maintain lifecycle of each connection from the first pool of reusable connections and to logically link the connections with the backend system.

11. The system of claim 9, wherein the memory further comprises:

a socket program code configured to link a connection from the first pool of reusable connections with the backend system on a system platform level; and

an event trigger program code to trigger an event indicative of the failed connection request for access to the backend system for the application.

12. The system of claim 9, wherein the memory further comprises:

a connectivity framework method program code to check validity of the plurality of connections from the first pool of reusable connections simultaneously, wherein the connectivity framework method program code receives the plurality of connections and returns at least one invalid connection.

13. The system of claim 9 wherein the memory further comprising:

a listener program code to receive an event indicative for the failed connection request for access to the backend system for an application; and

a connection pool manager program code to create a connection pool.

14. The system of claim 9, wherein the memory further comprises:

a communicator program code to send a message to the second server node indicative of the connection error.

15. A non-transitory machine readable medium having instructions tangibly stored therein which when executed cause a machine to perform a set of operations comprising:

maintaining a first pool of reusable connections in a first server of a distributed computer system, wherein each connection from the first pool of reusable connections provides access to a backend system linked to the distributed computer system via a network for at least one connection request processed at the first server of the distributed computer system;

detecting a connection error at the first server of the distributed computer system, wherein the connection error indicates failure of a connection request;

removing at least one invalid connection from the first pool of reusable connections responsive to the connection error; and

triggering a validation of a second pool of reusable connections at a second server of the distributed computer system responsive to the connection error, wherein each connection from the second pool of reusable connections provides access to the backend system for at least one connection request processed at the second server.

16. The machine readable medium of claim 15 wherein detecting the connection error at the first server comprises:

generating a connection request by an application executed at the first server to access data in the backend system; and

routing the connection request through a connection from the first pool of reusable connections providing access to the backend system at the first server.

17. The machine readable medium of claim 15, wherein removing the at least one invalid connection from the first pool of reusable connections at the first server comprises:

identifying simultaneously a set of invalid connections from the first pool of reusable connections providing access to the backend system; and

destroying the identified set of invalid connections.

18. The machine readable medium of claim 15, having further instructions tangibly stored therein which when executed cause a machine to perform a set of operations further comprising:

creating a valid connection at the first server providing access to the backend system when no valid connection exists in the first pool of reusable connections and the backend system is accessible.

19. The machine readable medium of claim 15, wherein triggering validation of the plurality of connections at the second server comprises:

sending a message to the second server, the message indicative of the error detected in the first server.

20. The machine readable medium of claim 15, wherein triggering the validation of the second pool of reusable connections at the second server comprises:

sending a message to the second server when there is no valid connection in the first pool of reusable connections providing access to the backend system on the first server.