+1 It's no longer a necessity. When we cooked up the Zend library, we realised that just by adding a subscription store we could handle both cases very easily. The introduction of automatic refreshes just confirmed that async would be the subscriber standard.
Paddy Pádraic Brady http://blog.astrumfutura.com http://www.survivethedeepend.com OpenID Europe Foundation Irish Representative ________________________________ From: Blaine Cook <[email protected]> To: pubsubhubbub <[email protected]> Sent: Thu, March 4, 2010 12:10:03 AM Subject: [pubsubhubbub] Removing Async / Sync Hi all, Mike, Alexis, and I had a very productive Thursday in London discussing the finer points of the PSHB spec; herewith a few proposals to improve the specification and hopefully enable some functionality that many of us are interested in. The first proposal is to remove the sync/async hub.verify parameter; chatting with Brett, it seems that this parameter used to be meaningful, but with the addition of automatic subscription refreshing, subscribers must now effectively support the async mode, and all subscribers must effectively support the sync mode in order to avoid timing issues. The consensus in London was that removing the distinction simplifies the spec, simplifies the implementation of hubs, and has virtually no impact on subscribers. In addition, it has the positive side-effect of ensuring that subscribers must understand a common and consistent set of subscription response codes; more on that to follow. It's worth noting that this change is backwards-compatible, in that hubs can safely ignore the hub.verify parameter so long as they employ synchronous verification in all cases (which is what the reference hub does already), with the slight modification that subscribers may receive 202 Accepted responses in reply to verification requests at any time. A diff against Version 0.3 of the PSHB spec, and the complete modified spec is included. b.
