user manual

70 BES Developer’s Guide

The Borland IIOP connector

The IIOP connector is software that is designed to allow an http web server to

redirect requests to the Borland web container. The Borland Enterprise Server

includes the IIOP connector for the Apache 2.0 and Microsoft Internet

Information Server(IIS) versions 5.0, 5.1 and 6.0 web servers. The job of

handling the redirection of http requests is split between two components:

■

a native library running on the web server.

■

a jar file running of the web container.

BES supports clustering of web components. The Borland IIOP connector

uses the IIOP protocol. The following unique features are provided:

■

“Load balancing support” on page 70

■

“Fault tolerance (failover)” on page 71

■

“Smart session handling” on page 72

Load balancing support

Load balancing is the ability to direct http requests across a set of web

containers. This enables the system administrator to spread the load of the

http traffic across multiple web containers. Load balancing techniques can

significantly improve the scalability of a given system. The Borland IIOP

connector can be configured to offer load balancing in the following two ways:

■

“OSAgent based load balancing” on page 70

■

“Corbaloc based load balancing” on page 70

OSAgent based load balancing

This is simple to achieve and requires the least amount of configuration. In this

setup, you start a number of Borland web container instances and name the

IIOP connector in those Borland web container with the same name.

For more information about setting the name attribute, go to Chapter 5, “Web

server to web container connectivity”.

Apache does load balancing across Borland web container instances for each

request. Essentially, Apache does a new bind for each request. The newly

started Borland web container containers can be dynamically discovered.

Important All Borland web containers and Apache must be running in the same ORB

domain; osagent based load balancing is not possible in cases where you are

using different Partitions on different ORB domains.

Corbaloc based load balancing

This approach uses a static configuration of the web containers that make up

the cluster. However, it can span ORB domains. In this case you specify the