Types of Hosting

Choosing the right kind of hosting can be a minefield for the uninitiated. So, before you decide that you can buy a hosting account somewhere else more cheaply than your web company is offering, consider the risks and factors involved before you decide to “go it alone”. You should think carefully before you decide how your web hosting will be delivered.

The following diagram shows the different layers of hosting – the green bars show the responsibility of your chosen partner compared to the type of hosting; for example, dedicated hosting means that you provide and manage everything from the business process layer down to the operating system layer and your hosting partner provides and manages the rest.

A lot of hosting companies do not own the data centre layer and many do not even control the networking layer. Instead they rent space from the data centre and install and run their own servers. This is the device, operating system and application infrastructure layer. Although this falls under “managed hosting” on the diagram, service level varies significantly. How many servers, what type of server and how many customers they share on each server all affect their levels of pricing and reliability. Web companies (like us) generally specialise in the application and business process layers and outsource the rest.

The important message is that unless you are an IT professional or hosting expert, have a dialogue with your web company so that you make an informed decision and not just one based solely on price – after all, you get what you pay for!

Here is a summary of the different types of hosting you may have heard about.

Shared Hosting (aka Virtual Hosting)
Shared Hosting is a hosting account where you rent disk space on a server which is partitioned and shared among many different users (websites). This is the most common form of hosting that you can find on the Internet today and is a cost effective way to getting started but there are pros and cons. Prices for shared hosting start from as little as £50 per year.

Pros:

• Inexpensive
• Easy to purchase
• Requires zero management (in most cases)

Cons:

You are competing with other unknown websites on the same server websites for access, which means:

• You may experience slow performance at times when other websites are very busy (big databases, high visitor volumes, large emailings)
• Abuse of virtual hosting accounts can cause spam to block shared email queues meaning not all email will be sent or arrive (aka a denial of service attack)
• If one of the other websites crashes, it might crash the whole server meaning you’ll be offline until the ISP resolves it
• You have limited control over what you can achieve on the website which can make more complex websites harder to implement.
• Possible exposure to security risks – shared environments with large numbers of unknown websites can create unexpected security risks; think carefully about the information you capture on shared hosting
• Many virtual ISPs don’t offer anything more than email support. Response is improving, but in some cases we know people have waited 7-10 days for a response. What if this was for an urgent “the server is down” request?
• You have no control over who else is on the server with you – some ISPs host pornography and gambling sites, and these will cause you no end of problems with downtime, poor performance and general inconvenience; read their terms and conditions carefully!
• Check carefully that the package you want has all the right operating system and application infrastructure – when you hapilly give your FTP details to your web company you might find you have bought completely the wrong package and have to start again (I have seen it happen a few times)

Virtual Private Server (VPS), aka Virtual Dedicated Server
The next level up is a virtual private server. This is a technology that allows hosting companies to partition a server into a small number of completely separate virtual servers. So, although you are still sharing a server with other sites, this configuration ensures you have a completely isolated environment with dedicated resources – which means you effectively have your own server at a lower price than if you rented a whole dedicated server. Virtual Dedicated Server hosting starts from £350 per year.

Pros:

• Guaranteed resources – no competition for bandwidth
• Greater flexibility – You should have root access which allows you to install your own software, set up cron jobs and build a complete application with total flexibility and no restrictions (application infrastructure layer)
• Greater security – You have your own ring-fenced environment
• Greater reliability – Somebody else’s code isn’t going to affect your site

Cons:

• More expensive
• Requires greater technical knowledge, though most VPSs come with a good control panel to make things easier
• Easier to break things if you’re not sure what you’re doing

Where to Find a VPS Hosting
There are now plenty of VPS Providers. You can find many by searching Google for “virtual private servers” or “vps hosting” or looking in one of the many web hosting directories or forums. Virtuozzo by SW-Soft is the main commercial software that web hosts use to run virtual hosting services, but there are others. For instance vserver is similar in principle to Virtuozzo but is not as widely used. Open source vps systems exist in the form of OpenVZ (a subset of Virtuozzo), UML (User Mode Linux) and more recently Xen.

VPS hosting used to be the prerogative of the smaller web hosts primarily looking for a more geeky market but recently the bigger mainstream web hosts have moved into VPS’s. You’ll get a much more generous bandwidth allowance compared to shared/virtual hosting, and none of the problems that go with a shared host. Usually you get multiple IP addresses that are exclusive to your sites, which you will need for SSL certificate hosting and for running your own nameservers if you want to register domain names.

Many hosting providers will offer “premium” or managed support which includes a bit more hand holding – this is definitely recommended if you don’t have much experience with Linux, and are not confident about keeping your VPS updated. It’s worth talking to your web host about updating and installing software. If its a Virtuozzo system, the web host will have preinstalled templates for common applications such as Coldfusion which can be rolled out across many VPS’s thus cutting down on disc space inside your VPS and well as saving memory and resources on the “hardware node” it runs on. Quite often the VPS provider can roll out operating system updates and bugfixes across all their VPS infrastructure.

Dedicated Server, or Co-Location
This is where you have a whole server to yourself. In the co-location scenario, the server is purchased by your company directly and then installed at an ISPs data centre. In the dedicated server scenario, you rent the hardware directly from the data centre or hosting company.

The pros and cons for a dedicated server are similar to the VPS above, but you are responsible for everything that happens on the server, from the operating system upwards. This can have a significant management overhead, especially if something goes wrong and you need to fix it and don’t have the skills.

Prices for dedicated servers start at around £1000 per annum, and from about £4000 per annum for zero-downtime versions (depending on how critical your applications are).

In-House Server
Some people consider that running their own server on the end of their broadband connection at their office is a good option. Especially if they have had poor performance with any of the other options. However, running your own in-house server means you are fully responsible for the whole spectrum of infrastructure layers, from the cabling and access to the server, through UPS (uninterruptible power supply), hardware, operating system, application infrastructure, application and business process layers.

Pros:

• [A feeling of] Control

Cons:

• Performance will reduce dramatically when you have more web traffic (ADSL only has a small upstream bandwidth)
• You will need additional bandwidth to accommodate busy sites (SDSL is expensive)
• You need the IT skills to support the infrastructure, or outsource to get somebody to manage it – remember that you are a single server and this cost could be high as you are a single environment; hosting at a managed data centre spreads the cost as the team are on-site 24×7
• Security – you need to make sure your web server cannot breach you internal network.

About 4 years ago, we developed our first ecommerce system prototype for a client. We decided to host it at one of our satellite offices on a broadband connection as a demonstration project. However, after we applied a little SEO magic to the site, traffic jumped and very soon the ADSL connection became totally clogged with traffic – visitors could not access the website and we couldn’t access the Internet from the satellite office. We very quickly moved the site to a hosting facility who had plenty of bandwidth and decided to concentrate on what we were best at – the application and business process layers only. Remember that the more data your website responds with per visitor, the greater the peak bandwidth load will be, and an ADSL connection does not handle multiple concurrency well in such circumstances.