This patch specifies a set of options required to setup the socket
keepalive feature of pymemcache (dogpile.cache) cache backend.
Original oslo.cache change:
https://review.opendev.org/c/openstack/oslo.cache/+/803716
Co-Authored-By: Grzegorz Grasza <xek@redhat.com>
Depends-On: https://review.opendev.org/807851
Change-Id: I683f1328ab68839b4877e91513cae206656a6ad2