Sorry for slight confusion. I am aware of the Elastic recommended mem settings. Im running Elastic with Mesos/Marathon and the assuption was that my Marathon settings where set to schedule a 40GB container at double what I have the -Xmx20G. But it doesn't unless we use the Mesos containerizer. Anyways...
I was curious how the JVM and Elastic behave inside docker regarding memory and mmap files. Since the container isn't restricted memory wise then the contaimer actually has 128GB available to it from the host.
So we have to consider that other containers includding other Elastic nodes like my coordinators are scheduled on that host. So it is possible that the containers will contend for available RAM.
The host has 128GB and 2GB swap which is pointless (need to revise the cloud image lol) and with mem_lock settings Elastic should be ok and not swapped out.