This was just one of those press releases that was so close to being right and yet was missing half the picture.

Chicago-based managed dedicated server provider, SingleHop, Inc., advises 
shoppers to be prepared to suffer through the dreaded "high traffic volume" 
warnings this holiday season as retailers may be hit with higher than average 
website traffic.  

That's really no surprise, after all I'm fairly certain my shopping alone is enough to cause outages. If you've run into an outage lately, my apologies. I'll be finished shopping shortly. I promise.

In any case, Zak Boca, President, SingleHop, goes on to posit a cause and a solution for these "outages".

"Normally a website is slow because the server cannot handle the amount of connections 
that it is receiving.  Too many visitors and you have a crash and can literally count the 
money you are  not making by the second," he adds. "The answer to this is load balancing.  
Load-balancing is done by routing requests across multiple servers. One visitor comes in, 
and they go to webserver 1, and the next visitor will go to webserver 2. It basically 
just serves as a director for traffic, and as such it allows a website to easily scale."

So here's where we get to dig into the cause (servers can't handle the high connection rate) and the solution (load balancing).

Unfortunately this answer is soooo dot.com it's not funny. While load balancing across a farm of servers will certainly allow a website to scale, there's more options to solving the availability challenges of today's high-volume sites than simple load balancing.

Zak correctly points out that one of the root causes of slow sites and outages is that servers can't handle the connections. Load balancing doesn't improve the ability of a server to handle connections, it simply spreads out the load across more servers. That's expensive because you need to invest not only in the cost of hardware and software, but maintenance, management and, yes, power and cooling. That adds up - quickly.

Application delivery controllers, on the other hand, offer up a solution that not only provides the load balancing you need but also increases the capacity of individual servers. That ultimately means the number of additional servers you need is lower than if you were to just implement some dot.com era load balancing solution. Application delivery controllers like F5 BIG-IP Local Traffic Manager (LTM) employ a technique often referred to as TCP multiplexing. That's a geeky term that really means "reuse connections to servers". By reusing connections to servers, the capacity of those servers is immediately increased, because they aren't spending extra time opening and closing connections. You're still going to run into an upper limit, of course, but it's often estimated that you can get as much as 33% more capacity out of a server by employing the connection reuse capabilities of an application delivery controller.

Zak also misses the impact of SSL on server capacity, and that's strange considering he's specifically discussing consumer retail sites; sites that sell products and therefore are nearly required  - at least by common sense - to secure all transactions. On the web that's typically accomplished by using SSL, yet another compute intensive process that can impact the capacity of a server.

Application delivery controllers, of course, can accelerate and offload SSL processing from servers. This means the server concentrates on doing what it's supposed to do - process transactions and serve content - while the application delivery controller manages the intense SSL encryption and decryption processing. Again, experts estimate that SSL processing consumes up to 30% of a servers resources. Offloading that processing to an application delivery controller can signficantly improve the capacity - and performance - of servers.

Load balancing has come a long way baby. It's no longer just about distributing the load, it's focused on ensuring fast, secure, and available application delivery.  Zak claims "load balancers" are expensive. Taking advantage of some of the advanaced features of today's application delivery controllers can certainly offset that expensive by reducing the number of servers - hardware and software - you need to support your (hopefully) growing customer base.

Imbibing: Water