[Nsi-wg] Notification queries.

[Henrik Thostrup Jensen]

On Wed, 5 Jun 2013, John MacAuley wrote:

> I have attached a discussion document that presents the two original 
> concepts discussed on the NSI call and an optimization to each.

I read: Why notifications combined with RPC as a base abstraction is a bad 
idea :-)

> I wanted to make sure I captured both so people do not think one was 
> ignored.  I believe the solution I have recommended (with hallway 
> agreement from Chin and Tomohiro) it the best short term option.  I will 
> have the completed WSDL ready to go so it can be committed upon 
> agreement this week.

Are there really going to be some many notifications that anything else 
than #1a is worth it?

Doing a querySummary to check if there are any new notifications, and 
doing a subsequent queryNotificationSync is WAY more expensive than 
including all the notifications in the query summary due to the overhead 
of establishing a TCP+TLS connections[1] which is 6 round trips in total. 
I can send an awful lot of notifications in that time. With our current 
scheme, adding a primitive for this is by far the most expensive solution.

1. TCP is 3 messages/3 roundtrips to set up a connection, where the last 
message/roundtrip can include data. TLS is 12 messages/4 roundtrips, where 
the first one can be included in the initial TCP data message. Totally we 
are looking at 15 messages and 6 round trips.


     Best regards, Henrik

  Henrik Thostrup Jensen <htj at nordu.net>
  Software Developer, NORDUnet