I'm seeing that when I upload a jar through the rest API, it looks like only
the Jobmanager that received the upload request is aware of the newly uploaded
jar. That worked fine for me in older versions where all clients were
redirected to connect to the leader, but now that each Jobmanager accepts
requests, if I send a jar upload request, it could end up on any one (and only
one) of the Jobmanagers, not necessarily the leader. Further, each Jobmanager
responds to a GET request on the /jars endpoint with its own local list of
jars. If I try and use one of the Jar IDs from that request, my next request
may not go to the same Jobmanager (requests are going through Docker and being
load-balanced), and so the Jar ID isn't found on the new Jobmanager handling
that request.
