If the word Co-location isn't in your ISP's vocabulary then your business is at risk. With lessons learnt from the United States we now realise that the future of all Web Hosting lies with Co-location.

Servers of all kinds like Mail Servers, Web Servers and Name Servers are connected to the Internet by permanent, high-speed connections. Any computer permanently connected is known as a Host and when the term Hosting is used, it usually refers to Servers that perform functions like serving Web pages.

Web Hosting companies usually keep several hundred Websites on one Server. This can be restricting however, as programming work done on these Shared Servers may compromise the reliability of that Server. If for example, a customer writes code that clashes with other programs, errors may force the Server to stop serving Web pages. As a result, some companies prefer to run their own Dedicated Server, so to avoid these types of errors. Among other things, this also gives them more control over security and the choice of which applications take priority when resources are running low.

As well as the network connecting them to the Internet, the location in which these Servers reside is critical to keep them running day and night. Companies offering Internet services need to ensure the environment their Servers reside in, has had all potential problems safe-guarded against. To avoid the large costs involved in constructing and maintaining these environments, it is usual for a number of companies to share premises. So what is Co-location, Colocation or Collocation ? Simply, it is sharing a location with others. Servers kept in these shared environments are known as Co-located Servers or Colocated Servers.

In the past, a suitable environment may have been in a computer room in a companies offices, however the incredible growth of the Internet has meant that higher specification buildings are built, specifically designed for housing computer equipment. Internet Exchanges, like LINX for example, are the meeting point for a large proportion of Internet traffic and the communications equipment used to run an Internet Exchange requires strict environmental controls to aid reliability. Professionally maintained buildings designed to house such equipment are called Data Centres or Data Facilities. Companies providing these buildings are known as Facility Management companies and facilities are built with the following in mind:

Physical security is critical to the success of a data facility. There have been occasions in the past when rather than compromising a Server through the Internet, intruders have compromised the security of the building in which it resides. Measures put in place to prevent this type of attack include: perimeter warning devices, alarms connected to the local police station, security cameras, twenty-four hour staff and key-card access prohibiting entry to certain areas of the building. These facilities are constructed with anti terrorist precautions employed.

Backup Power is essential in the event of power failure, even at a national level. Redundancy is usually in the forms of a backup generator or batteries that may serve the entire facility for the duration of a power outage. Facilities will also usually have two connections to the source at the power station, offering redundancy should one fail. To prevent fluctuations in the power coming into the premises, expensive filtering equipment is used. In the event of the main power feed causing problems, an Uninterruptible Power Supply is used to switch quickly and seamlessly from one feed to another, so Servers have no disruption to their power supply.

Air-conditioning keeps the atmosphere clean to avoid dust affecting sensitive equipment. Air can be piped upwards through the floors of the facilities and then recycled or refreshed by powerful conditioning units. Temperature control is essential as when a large amount of power is used, inevitably lots of heat is generated. If any area of a data facility suffers from too much heat, equipment sitting in these areas would eventually fail and cause a loss of service. Constant monitoring and thermostat controls allow large processing units to circulate cooled air, to correct any imbalance in the temperature of a room.

Geographical locations may pose the facility problems. As well as avoiding the close proximity of rivers and train lines, the design of a data facility should give some protection against Natural Disasters. Floors in the facility are usually raised well above ground level, guarding against minor floods that may cause a loss of service. Under the raised flooring there may also be a moisture detection system, warning against even a single drop of water. To avoid power fluctuations experienced within residential areas and deliver the capacity of power required, the only feasible location for a facility may be within an industrial estate. In the United States, a large number of Servers are housed on a known earthquake zone. Incredibly, one precaution taken is hanging the Servers on a harness, inside the rack or cabinet in which they are installed, to allow some movement in the event of an earthquake.

Electromagnetic damage is possible as sensitive equipment can be affected by invisible radio frequencies. Cabling inside the facility should be shielded against interference from other electronic devices. Due to this invisible hazard, most facilities strictly prohibit the use of mobile phones.

Fire detection and prevention are an absolute must in any data facility. Constant heat monitoring is aided by a smoke detection system, alerting the staff on-site immediately or closing certain areas of the facility off, to contain the problem. A fire suppression system will spray gas or a fine water-based mist to suffocate a fire, without directly damaging the equipment. Sophisticated air filtering systems are so sensitive that even when plastic starts to smoulder, well before a flame or fire, staff will be alerted. Suppression systems in many facilities have the power to stop all access to a sealed room and flood it with gas, to prevent a fire from spreading. In older systems toxic gas poses a serious risk to humans, so staff are followed around the facility by automated systems and warned immediately if any room is about to be sealed. Newer human-friendly systems replace the gas element with other substitutes.

The Future

As the majority of the Internet still resides in the United States, experience gained there usually fuels technological advances in Europe. We should be aware of the power limitations in the States, where data facilities are drawing too much power for the power stations to supply, causing blackouts. Consider the number of potential hazards in an office environment. Servers should only reside in a data facility and one that is near to an Internet Exchange, for optimum network connectivity. Compared to having a database system designed the cost, of housing your Server securely and receiving guaranteed network performance, is relatively low. Colocation companies offer Service Level Agreements on most elements of their service, paying compensation in the event that they fail to meet their guarantees.

If you are considering running a Website or your own Server, make sure your provider is housing its Servers in a data facility to minimise disruption to service. This will ensure your business is in the safest hands.