Before I slam shared website hosting completely, I feel I need to make a point of clarification. I do provide web hosting services and technically it is shared web hosting. However I have gone to great lengths and cost to build a non-typical environment. A fully managed load-balanced environment where alerts are sent any time performance levels are not what they should be, etc.
My point: I’m knocking the budget shared plans (read ‘GoDaddy’ and the likes), not all shared website hosting universally.
What a Website Attack Looks Like
Take a look at the above graphic. The graph is chronological view of CPU usage on a server spanning about 24 hours. CPU levels are just one the things we monitor to ensure servers are healthy but I am using it here as it gives a clear model of an attack underway.
In this particular graph a single WordPress website is being bombarded with comment spam at a super high rate. This particular sever hosts many web sites. However you can see here how a single site under attack can quickly eat up resources that the other sites rely on as well.
Server resources are not infinite and in this case and many like it, we have a single site (a normally low traffic website) consuming the majority of the server resources.
What This Has to do with Shared Hosting
Typical ‘budget’ shared hosting accounts are those that are loaded up on a single server and then left to share all the resources (CPU, drive space, memory and bandwidth) a server has.
Now consider for a moment, how a hosting company makes money… the more sites they squeeze on a shared server the better… for them, not you.
With each site that is loaded up on a shared server, fewer resources are then available for all the sites being served by that particular machine.
On a Good Day
On a day when no one on that shared server is subject to any kind of attack, your site is still competing for resources. Someone else’s success immediately becomes your curse, as they drive traffic to their site your site performance can be effected as they use more than their ‘fair share’ of the available resources.
On a Bad Day
One of the sites on the server becomes subject to an attack. Attacks can last hours or even days if nothing is done to stop them. Now in this scenario you may notice your site is not performing as well as usual, it loads slower etc. However attacks can become so bad that they basically bring the victim server to a halt. This is called a DoS or Denial of Service attack. Now your site may down and the underlying issue actually has nothing to do with you. The situation will not improve until the attack ends, the site owner or hosting company intervenes and mitigates the attack.
What to do About It
I have said a hundred times and I will say it again; Your website is a 24/7/365 window into your organization, this is NOT the place be cheap. Not all hosting plans are created equal, budget plans are generally s**** (yea, I said that) and if up time is important to you managed web hosting, dedicated environments and/or virtual private environments may be the way to go.