Basic HTML Version
Traditionally, server load balancing has
been viewed as something only large
enterprises needed to worry about
and nothing more than a costly and
unnecessary expense for SMEs. But
that was back when the Internet was
less important and most SMEs ran
their businesses using just a couple
of servers. Today, the number of
servers used by SMEs can often be 10
or more, while web traffic has grown
exponentially.
So what is load balancing? The
basic idea is to share internal network
traffic and incoming connections
across multiple hardware devices.With
back-end applications such as sales and
order processing, customer relationship
management, HR and billing being
integrated and web-enabled, reliability,
scalability and performance are essential.
For e-commerce companies, a server that
keeps timing-out as it can’t cope with the
level of visitors will damage your image
and reputation and result in lost business.
During a typical business day, staff will
arrive and access their email servers to
send and receive messages and log onto
their business applications. They may
use services such as video conferencing
and rely on internet-based voice,
data and messaging; while clients and
suppliers access company portals and
customers come to your web site. This
high level of activity continues to rise
until the business day winds down and
traffic slows.
In effect, load balancers are like
the traffic police; they keep the traffic
moving. A load balancer solution allows
you to plan for handling increased traffic
by ensuring that it is directed to servers
that are performing best and have
spare capacity based on factors such
as concurrent connections and CPU/
memory utilisation. And if a server or
application fails, the user is automatically
re-routed to another functioning server.
To further enhance and secure
the user experience, particularly for
transaction-based web services, some
load balancers also enable processor-
intensive SSL handshake and encryption/
decryption processes to be removed from
the servers. This offloading dramatically
increases web server performance, while
decreasing the time and costs associated
with secure transactions.
The Microsoft Factor
Another big driver for server load
balancing among SMEs is the list of
changes Microsoft has made to its core
server architecture in Exchange 2010
Networks
Making the case for
server load balancing
Leigh Bradford, UK
sales manager at KEMP
Technologies, explains what
server load balancing is and
why you may need it.
including the use of Exchange Client
Access Server (CAS) to handle client
connections. This makes load balancing
necessary to automatically re-route and
reconnect users to optimised servers to
avoid poor performance and deliver high
availability.
Law firm Hill Dickinson faced these
issues and is now using a pair of KEMP
load balancing appliances to ensure high
availability and resilience for its new
Microsoft Exchange 2010 messaging
environment.With more than 190
partners and 1,300 staff operating from
UK offices in Liverpool, Manchester,
London, Chester and Sheffield as well
as Athens and Singapore, Hill Dickinson
upgraded its Exchange email platform to
meet business performance and growth
requirements.
The two load balancing appliances
alongside resilient Exchange Servers
provide load balancing of the Outlook/
OutlookWeb Access (OWA) connections
across multiple HUB/CAS servers in both
their data centres.
“The load balancers are simple to
use with powerful reporting that we are
integrating into our overall monitoring
solution,” said Charlie Muir, Head of
Service Integration at Hill Dickinson.
“We are now also using the load
balancers for other key services including
fronting our recently installed Citrix
environment and our new BigHand digital
dictation service.”
The Lync effect
Many SMEs adopting Microsoft SharePoint
and Lync Server unified messaging
technologies are also discovering the need
for load balancing. For example, Lync has
to support real-time VOIP traffic flows
that are jitter- and latency-sensitive. In
fact, Microsoft increasingly recommends
the use of server load balancing to
optimise performance and resilience of all
these applications.
The complexity and scale of
technology required to run today’s
SMEs has brought with it many new
challenges to deliver performance, high
availability and security, but cost is
always a key factor.While large enterprise
load balancing solutions have been too
expensive and complex for most SMEs
there is a new generation of affordable
hardware or virtual load balancers aimed
at this market. SME IT is the same as
enterprise IT in everything but scale
and if SMEs want the functionality and
quality that enterprise CIOs take for
granted, load balancing has to be part of
the equation.
www.kemptechnologies.com
Leigh Bradford,
UK sales
manager,
KEMP
Technologies
magazine
39
01732 759725