On 12 Mar 2012, at 08:03, Dan Berindei wrote:


Well, probably not, because we only want to send keys to nodes that
actually need to store them...


Sending the whole tx as a multicast would certainly be more efficient
than what we do now with lots of targets.
With unicasts we could send only the minimum required data to each
target, but that computation would be complex and error-prone.

Well, this is what ANYCAST was all about initially, where JGroups would decide, based on the recipient list versus the total cluster size, on whether to send multiple unicasts or a multicast.  But we didn't end up doing this in the end, perhaps we need to revisit.

Bela, I'm guessing this thread was prompted by the poor performance in DIST that was reported, right?  I'd like to profile the test provided to understand where we should be looking in the first place.  E.g., is it the fact that we have too many RPCs?  Or maybe a locking/concurrency issue elsewhere, etc.  If you have done any of this analysis already, we should talk about that.

Cheers
Manik
--
Manik Surtani
manik@jboss.org
twitter.com/maniksurtani

Lead, Infinispan
http://www.infinispan.org