IP services loading issues
has always been in the minds of system administrators. Before load
balancing products like WebMux became available, the solutions are
either continuously upgrading to bigger server or using multiple
servers with multiple IP addresses access points. While the contents
or services provided by these servers are the same, different
clients are assigned to different servers.
Although the availability
of the load balancer has eased the load handing issues, how to
migrate the existing system with the minimum interruption is a challenge
In an one IP address, one server setup, adding a load
balancer and additional servers are straight forward. But in a multiple
IP addresses with multiple server setup, the best solution is not as
easy as it may appears.
While the most obvious solution
is to map all the domains into one IP address/port, it may not be
practical. Although most the web, ftp and e-mail accesses are using
domain names, other IP applications like many UDP services are often
accesses through hard coded IP address/port. It will cause a major service
interruption for the clients to ask the clients to re-program the IP
An obvious solution is to
set up multiple virtual farms that maps to a same group of servers.
Existing clients does not need to make any changes to enjoy the benefit
load balancing and fail over protection. While this solution sounds
simple and indeed it is very easy to setup with WebMux, many other
load balancer on the market does not support this important
function. Without WebMux's full flexibility of to let any
server/port to associate with any virtual farms, the clients may be
forced to re-program hard coded setup that can cause time,
recourses, lost of services and money.