#764 Add GPU support via --enable-features

[reneploetz]

This patch adds GPU scheduling support to Chronos the same way Marathon does it:

• you need to specify "--enable-features=gpu_resources" as parameter to enable it
• you can specify "--mesos_task_gpu=X" where X is an Integer to always allocate X GPUs for new tasks
• the REST API was extended to allow an optional field "gpus" alongside the usual "cpus/disk/mem" arguments to allow per-task GPU settings

The argument parsing code was adapted from Marathon (Features.scala / SchedulerConfiguration.scala) to provide the same behaviour.

This should fix #764

Signed-off-by: Rene Ploetz reneploetz@gmx.de

[brndnmtthws]

I'd like to see a little more in the unit tests for this, but aside from that, it looks good 👍

[brndnmtthws]

Please add a new test instead of changing this one.

[reneploetz]

I'll change the type back to DOCKER.
Do you want some tests for the MesosTaskBuilderSpec, e.g. whether a non-zero value would be applied? And do you want the commits squashed?

[gengmao]

@reneploetz According to http://mesos.apache.org/documentation/latest/gpu-support/, seems DOCKER type is not the right one

At the time of this writing, Nvidia GPU support is only available for tasks launched through the Mesos containerizer (i.e. no support exists for launching GPU capable tasks through the Docker containerizer)

[brndnmtthws]

@reneploetz let me clarify: I was suggesting you add an additional (new) test with the GPUs enabled, and leave the existing test unchanged.

[mindscratch]

What's the status of this PR? Right now, mesos-agents that have GPUs won't be offered to Chronos, which is problematic when all the agents have GPUs.

[reneploetz]

I'm afraid I never had time to create a pull request with proper tests as per review - feel free to do so. We were using Chronos with this patch in some product, but switched to another one a while ago.