Configuring the "mapport" feature of Edge Components Load Balancer
 Technote (troubleshooting)
 
Problem(Abstract)
How do I configure my advisors when using the Load Balancer "mapport" feature in IBM® WebSphere® Edge Server?
 
Resolving the problem
The mapport parameter maps the client's requested destination port number (the port configured on the Dispatcher machine) to the port number of the server used by the Dispatcher to load balance the client's request. The mapport parameter allows Load Balancer to receive a client's request on one port and to transmit it to a different port on the server machine.
You can use mapport to load balance a client's request to a server machine that is running multiple server daemons. The default for mapport is the client request's destination port number.

The mapport parameter applies to Dispatcher (using NAT or CBR forwarding methods) and to CBR.

The following commands are used to configure mapport:
  • For Dispatcher's NAT or kCBR:

    dscontrol server add cluster:port:server mapport value returnaddress rtrnaddress router rtraddress

Where, value is the port used by the application to listen for requests.

Consideration for advisors
When configuring advisors to query the health of your back-end servers in conjunction with the mapport feature, you need to still start the advisors on the port that has been configured (or added) to the cluster in the Dispatcher configuration. The advisor query will then be sent to the defined mapport of the back-end server.

For example, if the load balancer machine is receiving requests on port 123, and mapport is used to forward the request to port 456 on the back-end server:
  • Command:

    dscontrol server add www.mycompany.com:123:server1 mapport 456

  • Start the advisor using port 123:

    dscontrol advisor start http 123 http_123.log

For more details on configuring MAC, NAT and kCBR, refer to the Edge Component on-line information center.
 
 
 


Document Information


Product categories: Software > Application Servers > Distributed Application & Web Servers > WebSphere Application Server > Edge Component
Operating system(s): Windows
Software version: Load Balancer 5.1.1
Software edition:
Reference #: 1231013
IBM Group: Software Group
Modified date: Feb 21, 2006