The April 2016 OpenStack User Survey was recently released, and there is a strange result that shows the Modular Layer 2 plugin (ML2) as the second most popular Neutron network driver, used by 31% of respondents.
ML2 is a framework allowing OpenStack Networking to simultaneously utilize the variety of layer 2 networking technologies, compared to a single monolithic driver.
This is like asking which technology oriented TV comedy or dramas people like, and the result is:
- Silicon Valley
- Mr. Robot
- Big Bang Theory
You'd say, "HBO is a network, not a show", and this user survey has a similar problem.
Looking at the OpenStack survey, the top four drivers are:
- Open vSwitch (60%)
- ML2 (31%)
- Linux Bridge (21%)
- Juniper OpenContrail (14%)
The survey may have been worded improperly, and the respondents may not realize what's going on. The drivers that plug in to ML2 includes those for Arista, Cisco Nexus, Open vSwitch agent, Hyper-V agent among others. Let's try to understand it:
Given that the Open vSwitch is the most popular stand alone driver, it's likely that people use Open vSwitch's mechanism driver behind ML2.
Rather than quibble over the survey, which had a similar question and results last time, I want to evaluate the implications.
User seems to be most comfortable using a popular open source distributed multi-layer virtual switch, merged into the Linux kernel mainline so users are already familiar with it.
End-users seem to find Layer-2 necessary as it is compatible with traditional datacenter networking, and that choosing ML2 indicates that a mix-and-match approach is desired. Given that OpenStack is an open-source project, there is probably an affinity towards similar open-source projects.
It's good that a variety of choices are available and that I hope that future surveys dig deeper into what's really going on.