MOUNTAIN VIEW, Calif. — Like two tin cans and a string, communications channels are getting stretched to the breaking point and are sometimes victims of poor engineering decisions, said speakers at the annual Hot Interconnects conference here.
Facebook detailed its next-generation switch, Wedge, a high-profile response to the hyper growth of big datacenters. Others lambasted shortcomings of Ethernet, WiFi, InfiniBand, last-mile links, and communications silicon in general.
Silicon photonics is on the near horizon to help fill a few of the gaps, they said. But it brings its own challenges.
Fittingly, the event was held on the headquarters campus of Google, one of many cloud computing giants whose 100 megawatt datacenters are stretching networks to the breaking point. “The constant topic is: What’s the most cost effective, high performance way to build these networks?” said Andy Bechtolsheim, chairman of Arista Networks and serial entrepreneur.
The requirements in requests-for-quotes from datacenters have leapt a hundredfold over the last eight years, he said (see above). That’s because many datacenters have taken an approach to building flat, fast networks so applications can be blissfully unaware of the details of the network.
Arista specializes in building such nets based on the latest, fastest merchant switch chips it can get, mainly from Broadcom. The approach currently can put nearly a million servers on a single network using 10 and 40 Gbit/s connections (see below).
The job is software intensive. Ninety percent of Arista’s 600 engineers are writing software, Bechtolsheim said. It’s only going to get worse with companies such as Google calling for ways to get within milliseconds the precious data about traffic patterns, currently inaccessible on those chips.
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