On Tue, Jan 08, 2019 at 03:53:49AM +0000, Barrett, Brian wrote: > Sorry, that wasn’t clear. No, SRD does not require any job-like > indicators. It has a protocol to establish / invalidate reliability > state in firmware. My point was that whether or not there’s a > connection established under the covers, there’s no visible > connection to the user with SRD; A hidden connection manager makes a lot more sense. But still, the hidden and uncontrolled resource usage is probably still not so great for anything but a job-like HPC application. Any client/server thing is going to want to control this resource more finely. > characteristics). My experience (perhaps incorrect, but matching > with Gal’s expectations) with UD and RD is that consumers of the > datagram protocols don’t use a connection manager (because there > isn’t a connection). If this is a bad assumption, we’ll go back and > rethink our strategy. Well, sure sounds like there *is* a connection - you've just removed all visiblity and control over the underlying connection resources and state from the OS and application. UD has both connected and unconnected flows that are interesting, and as soon as there is a resource and state, generally, people will eventually find a reason to need control over that. (although probably not from a HPC workload perspective) For instance, most enterprise applications will want to tear down and restart their 'connection' - in the SRD perspective this means forgetting about all the connection state and setting it up again. In typical cases for other protocols this might select a different network multi-path, or side step some bug that was preventing forward progress. So, you can choose to hide all of this, but I wouldn't describe SRD as unconnected, more as 'automatically connected'. Jason
