[ofa-general] [RFC] the never ending search for SA scalability

[Roland Dreier]

 > > Don't you need a distributed SA for your idea to work?  Otherwise what
 > > happens if node A sets a service record at SA LID X, and then node B
 > > sends a query for that service record at SA LID Y?
 > 
 > My initial hope is that we can get away with replicating the data, and
 > using the existing SA protocol to keep it in sync.  For the example
 > you gave, SA LID X could forward the set to the master SA before
 > recording it locally.  SA LID Y would check with the master SA for the
 > data if it weren't found local.

You would need a protocol to invalidate any locally cached service
records when a service record is deleted.  And similarly for
everything else that needs to be kept coherent.  That sounds like what
I would call a distributed SA.

In any case, I don't see what having a mechanism for manual SA
redirect buys you.  I'm probably missing the point, but obviously
you're not planning on having sysadmins manually set the SA LID on
each node, which implies having some automatic agent that can set the
SA LID.  And given the existence of that agent, I don't see the
difficulty in putting that agent in the real SA and using the existing
SA redirect protocol to handle setting the SA LID.

 - R.