Radware Alteon Application Manual page 236

Alteon Application Switch Operating System Application Guide
Server Load Balancing
URL Hashing for Server Load Balancing
By default, hashing algorithms use the IP source address and/or IP destination address (depending
on the application area) to determine content location. The default hashing algorithm for SLB is the
IP source address. By enabling URL hashing, requests going to the same page of an origin server are
redirected to the same real server or cache server.
Load Balancing Non-transparent Caches
You can deploy a cluster of non-transparent caches and use the virtual server to load balance
requests to the cache servers. The client's browser is configured to send Web requests to a
non-transparent cache (the IP address of the configured virtual server).
If hash is selected as the load-balancing algorithm, Alteon hashes the source IP address to select
the server for SLB. Under this condition, Alteon may not send requests for the same origin server to
the same proxy cache server. For example, requests made from a client to
http://radwarealteon.com from different clients may get sent to different caches.
Figure 40: Load Balancing Non-transparent Caches
Configuring URL Hashing
You can direct the same URL request to the same cache or proxy server by using a virtual server IP
address to load balance proxy requests. By configuring hash or minmisses as the metric, Alteon uses
the number of bytes in the URI to calculate the hash key.
If the host field exists and Alteon is configured to look into the Host: header, Alteon uses the Host:
header field to calculate the hash key.
To configure URL hashing
1. Before you can configure URL hashing, ensure that Alteon is configured for basic SLB with the
following tasks:
— Assign an IP address to each of the real servers in the server pool.
— Define an IP interface.
— Define each real server.
— Assign servers to real server groups.
— Define virtual servers and services.
— Configure load-balancing algorithm for hash or minmiss.
— Enable SLB.
— Define server port and client port.
For information on how to configure your network for SLB, see
236
Server Load Balancing, page
Document ID: RDWR-ALOS-V2900_AG1302
165.