Thursday, August 15, 2013

Data Centre

A modern data centre is a futuristic fusion of library, aircraft hangar and operating theatre. Assuming you could get past the stringent security, you would wander the tiled floors of a vast hall, bathed in air-con chill and calmed by the ambient hum of cooling fans.

Data Centre tourist view

The aisles of servers and network equipment you see above looks quite different to a normal office. Those dense racks may be powering Google searches, or storing billions of facebook pages or running some corporate intranet, but the fundamental design principles are just the same.

Data Centre architecture for web services

Most sufficiently-large networks are three-tier constructions. In the centre is a high-speed backbone - the core network - which is optimised for high-throughput of data packets and connects to the outside world: the Internet, other corporate sites, the Extranet.

Attached to the high-speed core is an aggregation layer. This concentrates the traffic from large numbers of smaller local area networks and provides a home for network services such as: firewalls, security systems (ID&P), monitoring systems, caches, SSL accelerators, load balancers and the like.

Finally we have the access layer: switches which directly connect to those masses of servers and provide their primary network connectivity. In a smaller network, the access and aggregation layers may be merged.

In a certain sense, the essence of data centre design comes down to the architecture diagram shown above.