Load Balancing with Cisco CSS 11000 and WebSphere Portal V5

Introduction

IBM® WebSphere® Portal V5 provides an environment to build and deploy sophisticated
Web-based applications, called portals. A portal is a Web site that provides users with a single point
of access to Web resources. As e-businesses grow, they roll out more advanced Web applications to a
wider audience. The e-business portal becomes another “face” of the company that serves its customers;
therefore, it is important for the portal to be available and to provide reasonable response times.

The CSS 11000 is designed for HTTP traffic optimization. The switch software adds a Web-based layer to
the switching mechanism. Requests are parsed so that intelligent decisions can be made using information
in IP frames, URLs, and cookies.

Requests coming into the CSS 11000 are distributed across a group of portal servers.
As demand grows, you might decide to add more servers. Because a single portal page is constructed from
many HTTP requests, each portal server can assume part of the load, reducing the page response time.
Also, if one of the portal servers fails, requests can be routed to another server in the group.

Setting up Cisco CSS 11000

When creating a load balancing configuration, you must configure services and content rules.
Services identify the actual individual server, and content rules define the CSS load balancing features.

Configuring services

Create a service for each WebSEAL host and set the keepalive type to http.
With http keepalive, CSS generates an HTTP request and checks the response to see if the service is
still active. If CSS determines that a service is no longer functioning, it removes the service from the
load balancing algorithm.

Listing 1. Configuring services with keepalive

************************** SERVICE **************************
service WPST01
ip address 192.168.120.61
keepalive type HTTP
active

service WPST02
ip address 192.168.120.63
keepalive type HTTP
active

service WPST03
ip address 192.168.120.65
keepalive type HTTP
activeservice WPST03

Sepcifying content rules

All content rules must exist under an owner. To specify the content rule to match all TCP traffic
on port 80, as shown in listing 2:

1. Set the protocol to be TCP.
2. Set the TCP port to be 80.
3. Add services to content rule to create pool of servers CSS uses for load balancing request for content.
4. Create a virtual IP address for the content rule. Customers use this address to access portal resources.

Listing 2. Content Rules

*************************** OWNER ***************************
owner IBM
content PORTAL
protocol tcp
port 80
add service WPST01
add service WPST02
add service WPST03
vip address 192.168.120.50
active

Advanced load balancing

If your portal application requires that all requests be handled by the same server, you must enable
advanced load balancing for the content rule. The arrowpoint-cookie method enables the content rule to
associate the client to a server based on the unique service identifier of the selected server.
Use the string command to add a service identifier for each service.
Then add the advance-balance command with the arrowpoint-cookie option to the content rule definition.

In Listing 3, the bold text enables advanced load balancing.
Listing 3. Content rule with advanced balancing

************************** SERVICE **************************
service WPST01
ip address 192.168.120.61
keepalive type HTTP
string WPST01
active

service WPST02
ip address 192.168.120.63
keepalive type HTTP
string WPST02
active

service WPST03
ip address 192.168.120.65
keepalive type HTTP
string WPST03
active

*************************** OWNER ***************************
owner IBM
content PORTAL
protocol tcp
port 80
add service WPST01
add service WPST02
add service WPST03
vip address 192.168.120.50
advanced-balance arrowpoint-cookie
active

Conclusion

To have an effective On Demand business, you must be able to adjust quickly to changing conditions.
The combination of the Cisco CSS 11000 and the WebSphere Portal cluster gives portal administrators the
flexibility to easily add additional servers as customer demand increases.