[throwaway5752]

CoreOS is Linux distribution. It has been tuned to be lightweight, secure, and highly compatible with Docker among other things.

Mesos is a job scheduler for large distributed systems based on a quick read.

edit: and to the point, it is very natural to consider Mesos slaves as running inside of Docker containers (which may be based on CoreOS)

[robszumski]

CoreOS contains a tool called fleet, which abstracts systemd into a cluster init system. fleet has scheduling rules such as "don't schedule more than 1 foobar on this box" or "schedule this app on a box with metadata region=foo" built in to it.

fleet doesn't aspire to do complex resource scheduling or high density bin-packing. The best way to accomplish these tasks is to use fleet to bootstrap more complex and higher-level services like Mesos, Kubernetes or Deis. fleet will make sure the components of those services are running in the cluster, even if machines die or are partitioned.

(CoreOS employee)

[presspot]

Or, more robustly, run Kubernetes, Deis, and Marathon — along with Spark, Hadoop, Cassandra, and so on, all Mesos, all on the same cluster. Mesos is the only technology capable of doing that at any scale.

[derefr]

It'd be very interesting if you know anyone who is doing this sort of thing (fleetd for bootstrapping a more "heavyweight" scheduler) in production, and could prod them to do a write-up on their system. It might inspire some more interesting PaaS products. :)

[robszumski]

Deis has been doing this successfully for a while now. Their work is all open source. Here's what the units look like to bootstrap all of their components: https://github.com/deis/deis/tree/master/deisctl/units

More info on the components: http://docs.deis.io/en/latest/understanding_deis/architectur...

The Kubernetes project has also documented a getting started guide for CoreOS: https://github.com/GoogleCloudPlatform/kubernetes/blob/maste...