Figure out your connection rate

From LB Wiki

One of the most important metrics with load balancers is the connection rate. Unlike most other network devices where bandwidth is the primary metric, load balancers act more like servers, where the connection rate is the primary issue.

So how do you go about figuring out the connection rate? Turns out, there's a pretty easy equation you can run that will give you a fairly good estimate of what you can expect in terms of a max connection rate. If you've got an idea of how many page views you get per day, or even per month, you can figure out the connection rate.

For example, take a site that is getting 20 million page views per month. This equation assumes you're using HTTP 1.1, which will pull a page, as well as all the page's associated images. Most browsers will use HTTP 1.1, and as long as your server isn't specifically set for HTTP 1.0, this equation should be sufficient.

The trick is to convert per month into per second.

Month to days: 20 million per month (20,000,000 / 30 days per month)
Day to hours: 666,667 per day (666,667 / 24 hours per day)
Hours to minutes: 27,778 per hour (27,778 / 60 minutes per hour)
Minutes to seconds: 463 per minute (463 / 60 seconds per minute)
Average connection rate: 8 connections per second.  

This is the average connection rate of course, and you're probably more interested in the peak. The peak can be estimated pretty well by multiplying the average by 3, which gives us a peak value of:

24 connections per second. 

Virtually every load balancing product on the market is capable of handling this level of traffic.

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