Data centre-as-a service: Why the connection is King

Expotential

#dcsukarticle http://www.dcsuk.info/n/fopz

One of the newer approaches to IT delivery which is definitely distinct from other similar models is Data centre-as-a-Service, or DaaS. In its pure form, this refers to the delivery of on-demand Virtual Data centres (VDC) delivered across a private network, rather than the public internet. Typically, these are offered on a per unit basis – be it per-CPU or per-GB of Storage, for example, and can be dynamically provisioned.

The primary benefit of this approach is that it allows customers to ‘own’ infrastructure but on an OPEX rather than CAPEX model. The ability to scale resources up and down and only pay for them when they are needed is perfect for highly dynamic and resource intensive compute environments, such as financial services.

This may sound similar to Infrastructure-as-a-Service (IaaS), but should actually be viewed as a distinct flavour. What separates DaaS from other similar approaches is its private nature. The resources served up in a true DaaS scenario should simply be managed like an extension of internal data centre resources. The key to enabling this is the delivery mechanism – the private network.

The network is often one of the most overlooked aspects of any cloud or ‘as-a-Service’ deployment, despite the fact it remains the critical backbone for delivering services. Trusting non-critical services to the vagaries of the public internet may be acceptable, but for something as critical as core data centre services a far more robust connection is necessary.

Two of the major issues and concerns end-user organisations have when moving to the cloud are security and performance. Where data might previously have been consumed by end-users over a highly secure corporate LAN, remaining within the firewall at all times, cloud and ‘aaS’ models potentially see data traffic go over the public internet, where it is inherently less secure.

That said, it is performance where this model really tends to fall down – ultimately a service is only as fast as the slowest part of the network, and by bringing ‘best-effort’ internet into the equation you are potentially introducing a major bottleneck into the network infrastructure.

By removing public internet from the equation, true DaaS delivers not only a more secure environment, but one which performs more reliably. True DaaS makes external virtual data centres available
on-demand as if they were simply additional internal resources and for this to happen, services on the WAN must behave as if they were on the local network. Ultimately, you need a LAN that acts like a WAN.

Ethernet is the perfect platform to create this environment because it allows customers to easily and quickly introduce connections to new sites and services – including DaaS - without having to reconfigure the existing design. A private Layer-2 or Layer-3 VPLS connection will allow DaaS offerings to be managed across the WAN as if they were local resources.

Furthermore, customers can begin to look at introducing end-to-end SLAs for their DaaS deployments. The lack of SLAs in cloud deployments has often been a sticking point and while cloud providers will often guarantee uptime of their services, these promises do not extend to the availability or performance of the connection into their infrastructure. With a private VPLS connection, IT departments can have dedicated bandwidth and put in place SLAs with their service provider to ensure optimal performance.

The importance of private connections in DaaS deployments is magnified by some of the use cases where it is proving extremely popular. One of these is Business Continuity / Disaster Recovery – an initiative on which organisations are typically reluctant to invest upfront in dedicated infrastructure. In the event that an organisation is forced to fail over to a DaaS environment, ensuring a dedicated high-performance connection to those critical resources is of paramount importance. If the business is reliant on remotely deployed resources, delivering them over the internet is a potentially risk-laden approach.

Another popular use-case is Test & Development – another area where recreating the performance of the local data centre is crucial. In order to successfully test application performance for example, the infrastructure delivering those applications must behave and perform as it would on the local network. With DaaS delivered over a high-speed VPLS WAN, this is eminently achievable.

As organisations begin to assess DaaS as a viable alternative to in-house data centre resources, the supporting network must not be overlooked. Not only is the network the critical interface between the externally-hosted infrastructure and the local IT resources, but it is the key enabling technology that separates DaaS from a host of other similar models. Private VPLS-based networks blur the traditional LAN-WAN cloud perimeter, and create a highly responsive and flexible environment over which the IT department can have complete control.