From LB Wiki

The problem is all too common: You're an small to medium-sized business, and you're venturing into the world of application delivery/load balancing.

Getting the benefits of load balancing/application delivery are more affordable than they've ever been, and you don't even need to resort buying gray market gear off eBay.

As the load balancing/application delivery/application switch market evolved, a new tier of vendors and products has emerged. Instead of catering to the feature hungry Enterprise space, these vendors and their products are geared towards the SMB.

There are now several vendors that offer full-fledged Layer 4-7 load balancing with prices that come under $10,000 (and often less than $5,000) for a complete pair.

Defining the Value Market

When load balancing became a must-have part of any web infrastructure in the latest 90's, there was not value market. Load balancers were aimed directly at the Enterprise market: Fortune 500 companies and cash-drenched startups.

Criteria

Because of the multitude of vendors, even in the value market space, it's important to outline a few must-have attributes when considering a product. At the very least, a product should have the following going for it:

• Less than $5,000 per unit (less than $10,000 total for a redundant pair)
• The ability to perform cookie-based persistence
• The ability to terminate an SSL session (either in software or hardware)

These are the criteria for this Buyer's Guide. If a product does not have at least these three attributes, I wouldn't recommend even considering it. The reasoning is pretty simple: These are critical, highly useful features, and there are plenty of vendors that do offer these features for the price, so why go without?

Price, Performance, Features

For just about any piece of technology, it all comes down to three things: Features, performance, and price. So let's take a look at those in that order.

Features

The value market is a more modest version of the premium market load balancers, but the high end features that the value market doesn't have typically aren't needed at the SMB level. So what features do you really need?

Performance

Performance is everyone's favorite subject. It's easy to over-obsess about, but the fear of ending up with an infrastructure meltdown because of an under-spec'd product is certainly justified. Performance for load balancers in general are measured in four key areas:

• Throughput (the metric most are familiar and comfortable with
• Connection rate
• Concurrent connections
• SSL TPS

The most important metric for the small and medium sized business market and for load balancers in general is the connection rate. People often talk about throughput, but throughput is a simple matter for a load balancer to handle. It's the opening and servicing of new connections that tax a load balancer greatly. Take for example the following two scenarios:

• 10 connections per second, pushing 80 Megabits per second
• 5,000 connections per second, pushing 10 Megabits per second

In the first scenario, the load balancer is pushing 80 Mbps, but that load would put your average value market load balancer to about 5% CPU utilization. In the second scenario, 5,000 connections per second, at 10 Mbps, would put the CPU at around 80% (or more) for your typical value market load balancer.

Connection rate is your most important metric. So how do you figure out your connection rate? I've put together a page to help figure that out: Figure out your connection rate.

Throughput is only a concern when you're approaching 100 Mbps, and your load balancer only has 100 Mbps Fast Ethernet interfaces.

Do I Need Gigabit?

Certainly, if you think you're going to push more than 100 Mbps to the Internet, you're going to need Gigabit. If you're pushing 70 Mbps now, you'll want more than 30 Mbps worth of available bandwidth to grow. However, needing to push close to 100 Mbps is somewhat rare in the value market.

I've put together a mini-guide to help you determine if you really need gigabit.

Price

And now we come to price. There are at least three vendors that offer full featured products below $5,000:

• KEMP Technologies
• Coyote Point Systems
• Barracuda

There are two components to any networking product: The sale price and the support price. Because these devices are deployed on production networks sitting in-line with the traffic that is driving your revenue, you'll want to stay current on support for your product, so keep that in mind.

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