On 24 June 2016 at 17:40, Sandeep Chawla sandeep@cyngn.com wrote:
Hello,
I have a lava setup and right now running two single instance servers. These are pretty high end servers are handling 4-5 Android devices over USB
Are these devices connected directly to the server or are you using powered USB hubs? (Servers themselves don't always have more than 1 or 2 USB ports.)
I need to expand that to multi node setup with maximum DUTs connected to one dispatcher.
Caution: there are problems there, completely unrelated to LAVA, where the USB stack and fastboot end up causing jobs to sit there and wait for each other when there are multiple USB / adb devices on one dispatcher. We've moved to using LXC in LAVA V2 to solve these problems.
The target is only to have android DUTs so that implies a very stable USB hub and stack on the dispatcher machines.
I used a couple of off the shelf desktops in the past and the USB stack could not handle more than 1 device at a time.
That is a common experience - the Cambridge lab also limits the number of USB devices per dispatcher. Again, we're using LXC to isolate the USB devices and fastboot/adb from each other. The Cambridge lab is also working with a small company with some specialised USB devices (not cheap).
Any suggestions for hardware that is proven to be solid for dispatchers.
Mass market USB stacks can be a real pain - no matter what gets recommended, what it says on the label or packaging is no guarantee of the same chips inside.
Adding Dave to CC as he has more direct experience of the lab setup, including the Cambrionix units.
(Also, I'm about to head off to DebConf16 when I'll not be as easily contactable as usual.)