In the age of the cloud, not as many IT organizations are building data centers, but the ones that do decide to build one are clearly betting their business on it. A prime example is LinkedIn, which recently announced that it expects to go live with a new megascale data center facility, located in Portland, Ore., later this year.
For LinkedIn, this megascale data center is closely tied to recapturing the momentum it lost earlier this year when it reported a loss of $8.4 million for the fourth quarter, while projecting full-year revenues in the range of $3.6 to $3.65 billion. That was lower than the $3.9 billion that Wall Street analysts were expecting, which resulted in LinkedIn’s stock losing 44 percent of its value in a single day.
On the upside, LinkedIn also reported that membership in its social media network grew to 414 million, a 19 percent increase, and that mobile computing devices now accounted for 57 percent of all its traffic. The opportunity and challenge facing LinkedIn is developing new applications for its membership base that will drive higher margin revenues for the company.
To achieve that goal, LinkedIn decided to add a data center in a facility it leases from Infomart in Portland. The company declined to reveal how much it is spending on Project Altair, but the data center is optimized to house a mix of white-box servers and switches connected over a 100G network.
Yuval Bachar, LinkedIn’s principal engineer of global infrastructure architecture and strategy, says that the company initially will break that up into two 50G network segments to support a data center environment where up to 96 servers can be installed in any individual rack.
The most unique aspect of the Portland data center, known internally at LinkedIn as LOR1, is that it makes use of PSM4 optical interconnects. Those interconnects made it possible to segment the LinkedIn network using a Quad Small Form-Factor Pluggable (QSFP) interface that makes it possible to share two logical ports over a single physical port.
When all the costs associated with that approach are tallied, Bachar says that LinkedIn created a 50G network at a total cost per port that’s about half the price of a 40G optical network. Going forward, Bachar says that LinkedIn is hoping that vendors will actually deliver 50G Ethernet modules to make it simpler to transition to a 50/100G networking environment. He adds that in the future, LinkedIn expects to be able to deploy a 200/400G network using an eight-channel version of QSFP that will fix the current thermal shortcomings of the interface.
Building a New Generation of Apps
Bachar says LinkedIn is putting so much effort into this data center to reduce both capital and operational costs, while at the same time putting in place the infrastructure LinkedIn needs in order to build and deploy a new generation of applications.
“For us, it’s all about the user experience” he explains. “We need to be able to deliver sub-microsecond latency on an end-to-end basis.” To achieve that goal, the IT infrastructure environment needs to be disaggregated in a way that enables LinkedIn to automate much of the management processes, while simultaneously creating an IT environment that adds zero latency to the application environment.