Sun Java System Application Server Enterprise Edition 8.1 2005Q2 High Availability Administration Guide

Configuring HTTP and HTTPS Failover

The load balancer plug-in fails over HTTP/HTTPS sessions to another application server instance if the original application server instance to which the session was connected becomes unavailable. This section describes how to configure the load balancer plug-in to enable HTTP/HTTPS routing and session failover.

This section discusses the following topics:

HTTPS Routing

The HTTP Secure (HTTPS) protocol uses Secure Sockets Layer (SSL) to provide encryption an decryption of HTTP requests for secure communication. For HTTPS routing to work, one or more HTTPS listeners must be configured.

The load balancer plug-in routes all incoming HTTP or HTTPS requests to application server instances. However, if HTTPS routing is enabled, an HTTPS request will be forwarded by the load balancer plug-in to the application server using an HTTPS port only. HTTPS routing is performed on both new and sticky requests.

If an HTTPS request is received and no session is in progress, then the load balancer plug-in selects an available application server instance with a configured HTTPS port, and forwards the request to that instance.

In an ongoing HTTP session, if a new HTTPS request for the same session is received, then the session and sticky information saved during the HTTP session is used to route the HTTPS request. The new HTTPS request is routed to the same server where the last HTTP request was served, but on the HTTPS port.

Configuring HTTPS Routing

The httpsrouting option of the create-http-lb-config command controls whether HTTPS routing is turned on or off for all the application servers that are participating in load balancing. If this option is set to false, all HTTP and HTTPS requests are forwarded as HTTP. Set it to true when creating a new load balancer configuration, or change it later using the asadmin set command.

Note –

If https-routing is set to true, and a new or a sticky request comes in where there are no healthy HTTPS listeners in the cluster, then that request generates an error.

Known Issues

The Load Balancer has the following limitations with HTTP/HTTPS request processing.