If the term, “high-availability website” makes you think of companies the size of Amazon.com, never fear: as a small-to-medium business, there are many ways to make your website highly available. Best of all, it is possible to do so without breaking the bank.
Just what does high availability mean? It means simply making your website available most of the time. Availability is usually measured in percentages so, for instance, a site which is guaranteed to be up 99.9% of the time (three nines in geek-speak) can be down for 8.76 hours per year. A site with guaranteed uptime of “four nines” (or 99.99%) of uptime can be down for 53 minutes per year. To your website’s visitors, it can occur virtually undetected. It is important that you notice that I wrote “most of the time” and not “all of the time.” Truly non-stop computing is virtually impossible to achieve, is very expensive, and is not justified for most websites.
Small to medium-sized businesses can make their websites highly-available by following these steps:
1. Choose a web hosting company which stresses service over low prices. In the unlikely event that your web server goes down, you will probably receive a better response from a service-oriented hosting company. Ask hosting companies about how they handle emergency situations and how they will be able to assist you if their servers go down. If you can’t reach them by phone, you should be hesitant to trust them with your business.
2. Make backup copies of your entire website and databases from which you can recover individual files. The vast majority of website downtime results from individual files that are accidentally changed or deleted. Often, the fastest solution is to simply recover the file from the most recent backup. While you are checking on your backups, make sure that they cover more than just the previous night. If someone deletes a critical file on Friday afternoon but you do not discover it until Monday morning, can you still get it back?
3. Consider a cloud server instead of a dedicated server. By moving your web server into “the cloud,” you free yourself from dependence on a specific piece of hardware. If a computer fails or a disk drive fails, your web server can be magically moved to a new computer or a new disk drive. Such a migration usually takes just a few minutes and requires no additional work or cost to you.
4. Consider having a hot backup web server on stand-by. A hot backup contains copies of all of your files and databases and is kept in sync with the master database. If your primary server goes down, some manual intervention may be required (to update DNS records, for instance) but your site will be up and running again very quickly.
Finally, you may want to consider having multiple servers running 100% of the time, with load balancers on the front line. With this architecture, failures of any of the back-end servers are instantly alleviated by the load balancers which simply route all traffic to the servers which are still functioning.
