Everywhere you look, change is afoot in computer networking. As data centers grow in size and complexity, traditional tools are proving too slow or too cumbersome to handle that expansion.
Dinesh Dutt is Chief Scientist at Cumulus Networks. Cumulus has been working to change the way we think about networks altogether by dispensing with the usual software/hardware lockstep, and instead using Linux as the operating system on network hardware.
In this week's New Tech Forum, Dinesh details the reasons and the means by which we may see Linux take over yet another aspect of computing: the network itself. -- Paul Venezia
Using Linux as your network operating system
There are many differences between the modern data center and the traditional enterprise networks that preceded it. Data center applications are more Layer-3 savvy -- for example, they use L3 methodologies such as name service and service discovery instead of assuming their peers are all in the same subnet. Data centers can work around things like network failures, the fact that more traffic is east-west rather than north-south, and so on. But one point dwarves everything else: the monster scale of the modern data center
Thanks to server virtualization, there are tens of thousands to millions of endpoints inside a data center compared to the few thousand of yesteryear. The scale of virtual networks is also far more than that of traditional VLANs; not only that, these virtual networks are spun up and down at speeds orders of magnitude faster than their VLAN counterparts. Plus, the sheer number of servers means there is a lot more networking gear to manage than in traditional enterprise networks.
Thus, the scale and agility of modern data centers put data center networking at odds with the existing network models. Some problems, such as the number of virtual networks, required the development of new technologies such as VXLAN, while others have required a redesign of the network architecture deployed in the data center. But the problem of managing the network is not rooted in any failure of networking, rather in the design of the network OS.
How we got here
Not so long ago, although a lifetime in Internet years, routers and switches went from being Unix servers with a few NICs to black boxes that were optimized for packet switching and for running the protocols essential to their functioning as a router. In the beginning, the OS that ran on this black box was hardly an OS. It was more like a giant select loop executing various tasks based on what woke it up.