Automation of stress testing

[trgill]

Start with framework in:

https://stratis-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/scale-tests/

[mulkieran]

@bgurney-rh What are your feelings on this?

[bgurney-rh]

The original test script is in stratis-storage/stratisd#1426; it needs to be tuned to avoid running into a "storm" of oom-killer events that would ensue when the filesystems are created, and the buffer/page cache usage increases, potentially to a point where the kernel starts terminating processes to avoid running out of memory.

I made a quick table of buffer/page cache usage for specific filesystem counts in the test:

50 filesystems: 20 GB cache used
100 filesystems: 40 GB cache used
500 filesystems: 200 GB cache used

[mulkieran]

Ok. Moving to ci...