Communication multiplexor for use with a database system implemented on a data processing system

• US 20040122953A1
• Filed: 04/14/2003
• Published: 06/24/2004
• Est. Priority Date: 12/23/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Xue, Xun, Pereyra, Hebert W., Kalmuk, David C., Lind, Jon A.
• Granted Patent: US 7,246,167 B2
• Time in Patent Office: Days
• US Class Current: 709/227
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466

Abstract

A communications multiplexor includes dispatcher processes for monitoring client connections. The dispatcher processes detect activity on those connections, and then pass active physical (client) connections to agent processes for servicing. Transfer is done through specific connection queues that are associated with a set of agents. A multi-queuing structure permits pooling of agents on a set of shared resources thereby reducing time required to switch between different client connections. After an agent has serviced a given connection, the agent returns that connection to the agent'"'"'s dispatcher (there is a static assignment between connections and dispatchers), and then reads the next unit of work from the agent'"'"'s associated connection queue. This structure may be scalable while allowing optimal performance when passing physical connections between processes.

Claims

1. A database management system for a database for handling data access by a plurality of client connections, said database management system comprising:

a listener process; and

agent processes;

wherein said listener process detects active client connections containing client requests and passes said active client connections to said agent processes, and said agent processes execute requests for said active client connections against said database.

2. The database management system of claim 1 further comprising:

a dispatcher process; and

a connection queue;

wherein said listener process passes the detected active client connection to the dispatcher process, the dispatcher process passes the detected active client connection to the connection queue, the connection queue passes the detected active client connection to the agent process, and the agent process sends a reply related to the request back to the detected active client connection.

3. The database management system of claim 2 further comprising a shared socket pair used as an inbound queue for the dispatcher process.

4. The database management system of claim 2 further comprising:

means for using multiple queues to pass requests from dispatcher processes to agent processes; and

means for logically associating queues with agent process pools each maintaining an affinity with an associated queue.

5. The database management system of claim 2 wherein:

detected active client connections are passed from dispatcher processes to agent processes through socket pairs that are private to the dispatcher processes; and

the agent process requests the dispatcher process to pass descriptors for the detected active client connection through a shared socket pair.

6. A computer program product having a computer-readable medium tangibly embodying computer executable instructions for directing the data processing system to implement the database management system of any one of claims 1 to 5.

7. An article comprising:

a computer-readable signal-bearing medium; and

means in the medium for directing a data processing system to implement the database management system of any one of claims 1 to 5.

8. A method for multiplexing client connections within a database system implemented on a data processing system having a database, the method comprising:

having a listener process pass detected active client connections to respective agent processes, the detected active client connections each having a request embedded therein;

having an agent process execute a request against the database, the request extracted from a detected client connection; and

having the agent process handle shared memory read and write operations to process the embedded request.

9. The method of claim 8 further comprising:

having a listener process pass the detected active client connection to a dispatcher process;

having the dispatcher process pass the detected active client connection to a connection queue;

having the connection queue pass the detected active client connection to the agent process; and

having the agent process send a reply related to the embedded request back to the detected active client connection.

10. The method of claim 9 further comprising using a shared socket pair as an inbound queue for the dispatcher process.

11. The method of claim 9 further comprising:

using multiple queues to pass requests from dispatcher processes to agent processes; and

logically associating queues with agent process pools each maintaining an affinity with an associated queue.

12. The method of claim 9 further comprising:

passing detected active client connections from dispatcher processes to agent processes through socket pairs that are private to the dispatcher processes; and

having the agent process request the dispatcher process to pass descriptors for the detected active client connection through a shared socket pair.

13. A computer program product having a computer-readable medium tangibly embodying computer executable instructions for directing the data processing system to implement the method of any one of claims 8 to 12.

14. An article comprising:

a computer-readable signal-bearing medium; and

means in the medium for directing a data processing system to implement the method of any one of claims 8 to 12.

15. In a database system implemented on a data processing system, a communication multiplexor for executing requests against data contained in a database stored in the data processing system, the communications multiplexor implementing the method of any one of claims 8 to 12.

16. A computer program product having a computer-readable medium tangibly embodying computer executable instructions for implementing the communication multiplexor of claim 15.

17. An article comprising:

a computer-readable signal-bearing medium; and

means in the medium for directing the data processing system to implement the communication multiplexor of claim 15.