Down and dirty in a monster data centre
El Reg goes on tour with Rackspace
Cloud At 66,000 servers worldwide and counting, it’s hard to remember that 10 years ago Rackspace didn’t exist. Now its customers in its Slough data centre alone include the Ministry of Defence and Lloyds TSB. Use an Oyster card, or buy insurance from Confused.com, and your data is stored on one of the 16,000 Rackspace servers in the UK. And, of course, The Reg lives somewhere on its 5,000 square metres of floorspace.
Gartner puts Rackspace in the top right of its “magic quadrant. But what’s so clever about filling a building with servers?
Gary Boyd, data centre director of engineering and operations, let us through the secure doors into the parts where only rackers (the company’s name for its employers) who have a defined need can go.
Stop one on our tour was the cloud. Rackspace’s cloud services have been operational since January 2011, juiced by five 5-tonne “Huddles”, which bring provisioning time down from 10 days to a few seconds. One Huddle consists of 210 servers across 14 cabinets. The basic server spec is a dual Hex core, 12GB of RAM and three 500GB hard disks on a RAID5 configuration.
The basic server is built off-site by the manufacturer, and configured at the data centre: 116 components per cabinet, manually assembled. In the near future Rackspace will take delivery of pre-configured cabinets to plug in and connect up, so it can realise its dream of cabinets that no one touches from commissioning to decommissioning.
Burst your thirst
Bridging the worlds of cloud services and the traditional managed hosting servers on the floor, still is still the bread and butter of Rackspace’s business, is RackConnect. If you’re a hosting customer with bursty traffic – Christmas shoppers, a sporting event - RackConnect supplies a rapid link between managed hosting and public cloud servers. It is a Layer 2 connection between the two environments that guarantees equivalent security, but gives managed hosting customers the short-term capacity that they need to absorb demand.
RackConnect uses two devices: an F5 load balancer, and a Cisco ASA firewall to provide isolation for the traffic. It would lets customers use Rackspace hosting as a development platform to perform load testing for example; or simply let them burst to the cloud when they need it. Power and cooling are as much of a headache for Rackspace as for the rest of us. In Slough, each cabinet pulls between 1.5 and 3.5kW. The supply air temperature is maintained between 14 and 17C, the humidity between 40 and 60 per cent. The operational limit is 3.5kW per cabinet, without creating hot spots.
But for many data centres in the London area, the problem isn’t so much about hot spots as a lack of power. Rackspace is fortunate: it has space for one more data hall, currently under construction, and the power to supply it. A mess of ducting and concrete will be ready in eight months for 13,500 servers – almost doubling the data centre capacity – because the building has a supply up to 15MVA.
Yet Rackspace is still searching for fractions of a per cent efficiency. For example: “We would traditionally put in an isolation transformer at PDU level to get rid of harmonics,” Boyd says, “with new server technology, the risk of that has gone away … that gives us an extra 1.5 per cent that we were losing in distribution. We’re constantly looking for all these little areas.”
With its data centre approaching three years old – almost middle age in DC terms – Rackspace is in the middle of site selection for its next generation facility. What will be different?
Morphin power rangers
"In principle it will do the same things,” says Ricardo Degli Effetti, data centre manager, “but it’s going to be more efficient, more green.” The next generation will use outside air cooling, for example, when it comes on line in about 18 months.
The hot and cold aisles will be enclosed to minimise the mix of hot and cold air to improve the efficiency of the cooling system as a whole. The critical infrastructure will be more efficient too, simply because the equipment was not available four years ago, when Rackspace last went shopping: for example an uninterruptible power supply that is 98 per cent efficient, compared to 95 per cent for the current system.
Perhaps surprisingly, Rackspace isn't trying to sell a technology "secret sauce" as the foundation of emerging cloud services. It’s happy to show customers how it uses best practice, but relies for competitive advantage on its mantra of “fanatical support” – you don’t go long in the company of a racker without hearing this phrase.
It’s harder to work out what this means in practice, but Gartner buys into the Rackspace pitch big time, as this gushing paean shows: "Rackspace has long set the bar for customer service in the industry, with proactive, high-touch service and support … it has the industry's best practices in customer service, along with an excellent service culture."
Also, Rackspace believes that too much proprietary development will slow down the market, especially the adoption of hybrid cloud. For that to be a success, customers need to feel confident about interoperability and escape from vendor lock-in. To help this, in July 2010 it contributed the code that powers its cloud servers, together with NASA, to the Openstack initiative backed by Intel, Microsoft and Dell among others.
We have written about OpenStack elsewhere, but suffice to say here Rackspace is "very much behind the open source approach," says Boyd, "the industry needs to evolve. Rather than people spending time and effort to create intellectual property, we believe it should be shared." ®