As per https://www.mediawiki.org/wiki/Content_translation/Setup#Backend_Services, Varnish will help to make Content Translation fast using caching mechanism. Varnish for cxserver is not yet configure and it would be nice to have for Production. We need to configure Varnish on Beta, so that exercise for Production will be easy.
So, a temporary solution while we discuss and setup the "services" varnish cluster has been implemented via the parsoid varnish cluster. Requests with to the "cxserver.eqiad.wikimedia.org" hostname and with the "cxserver.eqiad.wikimedia.org" Host: HTTP header will be routed to the cxserver backends via the varnish cluster. For now, in the interest of not polluting the parsoid varnish caches, no caching is done at the varnish level. This is mean to change when we move the the dedicated "services" varnish infrastructure