Method and apparatus load balancing server daemons within a server

• US 7,058,727 B2
• Filed: 10/11/2001
• Issued: 06/06/2006
• Est. Priority Date: 09/28/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dingsor, Andrew Dwight, Fontes, Stephen Manuel
• Primary Examiner(s): WINDER, PATRICE L
• Application Number:
  US09/976,126
• Publication Number:
  US 20020083199A1
• Time in Patent Office: 1,699 Days
• Field of Search: 709/245, 709/225, 709/203, 709/228, 709/238, 709/230
• US Class Current: 709/245
• CPC Class Codes: H04L 61/00 Network arrangements, protocols or services for addressing or naming
• CPC Class Codes: H04L 61/25 of the same type
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]
• CPC Class Codes: H04L 69/161 Implementation details of TCP/IP or UDP/IP stack architecture; Specification of modified or new header fields
• CPC Class Codes: H04L 69/163 In-band adaptation of TCP data exchange; In-band control procedures
• CPC Class Codes: H04L 69/165 Combined use of TCP and UDP protocols; selection criteria therefor
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A method and apparatus in a data processing system for binding a plurality of server daemons to a destination address and port. A request for a connection from a client is routed using a destination address. A server daemon within the plurality of server daemons is selected to form a selected server daemon. The request is routed to the selected server daemon by changing the destination address to a server address for the selected server daemon. When a response is returned, source address in the response is changed to the original destination address.

Claims

1. A computer comprising:

a plurality of processes, wherein the plurality of processes service a destination address and have process addresses;

a packet routing layer, wherein the packet routing layer routes packets to the plurality of processes using destination addresses within the packets;

a dispatch layer between the packet routing layer and an IP layer, wherein the dispatch layer has a plurality of modes of operation including;

a first mode of operation in which the dispatch layer receives a packet from a client, wherein the packet includes the destination address;

a second mode of operation, responsive to receiving the packet, in which the dispatch layer identifies a process within the plurality of processes to service the client, wherein the process is an identified process;

a third mode of operation in which the dispatch layer translates the destination address to a process address for the identified process within the plurality of processes; and

a fourth mode of operation, responsive to the third mode of operation, in which the packet is sent to the packet routing layer.

2. The computer of claim 1, wherein each packet includes a source address and wherein the dispatch layer further includes:

a fifth mode of operation in which the dispatch layer receives a second packet from the identified process for the client; and

a sixth mode of operation, responsive to the fifth mode of operation, in which the dispatch layer translates a source address in the second packet from the process address for the identified process to the destination address of the packet received from the client.

4. The computer of claim 1, wherein the packet routing layer is a transmission control protocol layer.

5. The computer of claim 1, wherein the plurality of processes is a plurality of server daemons.

3. A computer comprising:

a plurality of processes, wherein the plurality of processes service a destination address and have process addresses;

a packet routing layer, wherein the packet routing layer routes packets to the plurality of processes using a destination addresses within the packets;

a dispatch layer between a TCP layer and an IP layer, wherein the dispatch layer has a plurality of modes of operation including;

a first mode of operation in which the dispatch layer receives a packet from a client, wherein the packet includes the destination address;

a second mode of operation, responsive to receiving the packet, in which the dispatch layer identifies a process within the plurality of processes to service the client, wherein the process is an identified process;

a third mode of operation in which the dispatch layer translates the destination address to a process address for the identified process within the plurality of processes; and

a fourth mode of operation, responsive to the third mode of operation, in which the packet is sent to the packet routing layer, wherein the second mode of operation includes;

a first submode of operation in which a determination is made as to whether a connection exists for the client;

a second submode of operation, responsive to a determination that a connection is absent for the client in the first submode of operation, in which a connection is created and a process within the plurality of processes is assigned to service the connection, wherein the process is the identified process; and

a third submode of operation, responsive to a determination that a connection exists for the client, in which a process assigned to the connection is identified and forms the identified process.

6. The computer of claim 3, wherein each packet includes a source address and wherein the dispatch layer further includes:

a fifth mode of operation in which the dispatch layer receives a packet from the identified process for the client; and

a sixth mode of operation, responsive to the fifth mode of operation, in which the dispatch layer translates the source address in the packet of the destination address.

7. The computer of claim 3, wherein the packet routing layer is a transmission control protocol layer.

8. The computer of claim 3, wherein the plurality of processes is a plurality of server daemons.

9. A computer program product for routing packets from a client to a selected process within a plurality of processes servicing a connection between a data processing system and the client comprising:

a recordable-type computer readable medium;

first instructions for receiving a packet for the connection between the data processing system and the client, wherein the packet includes a destination address;

second instructions, responsive to receiving the packet, for a dispatch layer between a packet routing layer and an IP layer to identify a process within the plurality of processes to service the client;

third instructions for translating, in the dispatch layer, the destination address to an intermediate destination address, wherein the intermediate destination address is an address for the identified process within the plurality of processes; and

fourth instructions, responsive to the translation, for sending the packet to the packet routing layer, wherein the instructions are embodied within the recordable-type computer readable medium.