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