Though the holiday season has come and gone it is still well worthwhile to develop a project plan to make sure that no element of your website has been overlooked as you prepare for the coming year and continued increases in web traffic. Should you overlook even one part of the infrastructure there is a real risk of downtime occurring which as everyone knows is bad for business and even your reputation.
Based on the results from the Ponemon Institute downtime costs as much as $5,000 per minute for website owners on average which converts into a staggering $300,000 per hour. Clearly it is important to take all the necessary steps to ensure business continuity.
As you know Server capacity is important, it is good practice to spread content across different servers with a series of backup servers that can be made available in the case of primary server failure, overload or even malicious attack. However beefing up your server farm is NOT the only step that you should take.
Load Balancers or Application Delivery Controllers (ADC’s) play a vital role in your website infrastructure. These load balancers have a number of important functions to perform that will both protect your content servers from being overloaded while at the same time providing website visitors and customers with a satisfying experience. You can think of the load balancers as traffic cops, constantly monitoring the web site traffic as it rises towards its peak and directing this traffic to the best performing content servers, while at the same time limiting new sessions to those that are heavily loaded.
Monitoring content server health at the Layer 4 level is not all that the leading load balancers do, they also monitor performance at Layer 7 (Layer 4 load balancers act upon data found in network and transport layer protocols (IP, TCP, FTP, UDP). Layer 7 load balancers distribute requests based upon data found in application layer protocols such as HTTP. This is a vitally important feature in effective load balancing. Layer 4 monitoring will tell your IT department how a server is performing in general and how it is dealing with requests for content from visitors to your website. Layer 7 monitoring on the other hand directly checks the performance of individual applications therefore providing a more 3 dimensional view of what is going on. Monitoring at Layer 7 could, for example, show you that your application that displays information about products that are available for purchase is performing well while at the same time your payment portal is being overloaded on the server in question.
An additional extremely useful feature of leading ADCs is their ability to cache content. The load balancers “learn ” about the most frequently requested web page content and maintain this information in cache so that users requirements can be served without the request constantly being passed to the content servers. It is advisable that load balancers are set up in high availability mode (HA -Two Load Balancers) for mission critical content load balancing. This means that should one of the load balancers fail the other will automatically take over as the second unit constantly monitors the performance of the primary device. With your ADCs installed you can relax and know your website will be ready for traffic increases in the coming.