Thanks for your inputs, Victor. In my app, it's a bit event driven.
We do writes and fire events and listeners then read - so we can't predict how soon the reads will come. Sometimes they came too fast, which is better for our app, if we can have a Cassandra DB level understanding that they won't miss the writes, if they come too fast :-) Or, if there is anything we should do to make sure that reads happen in an assured manner. On Tue, Jan 25, 2011 at 10:22 AM, Victor Kabdebon <victor.kabde...@gmail.com > wrote: > Again don't take it as a 100% sure answer because it is not an area that I > have really explored. > > So yes I think that reads are made from Memtables. > Theoretically yes, however it is very unlikely : your get must be build and > send before the commitlog updates the Memtable (which is like inserting in a > Memtable, a matter of microseconds). > Possible configuration : Just wait a second or so to do your "get" query (I > imagine that it works after one second because you don't report this > problem)... Other than that no not really. I have not done any application > with those time constraints. > > Best regards, > Victor Kabdebon > > 2011/1/24 Roshan Dawrani <roshandawr...@gmail.com> > >> On Tue, Jan 25, 2011 at 9:57 AM, Victor Kabdebon < >> victor.kabde...@gmail.com> wrote: >> >> As far as I remember, please correct me if I am wrong, on a one node >>> cluster : >>> First Commitlog is updated then almost immediatly after order is send to >>> the memtable to add this new insert. You might have a very short delay >>> between the two. I don't know your configuration but especially if you >>> insert from a distant server to a node you should look at their sync.. >>> Otherwise if it doesn't appear I can offer no explanation for this >>> behavior... >>> >> >> As of now, I am on an app server with an embedded cassandra server, so no >> possibility of clocks out-of-sync. >> >> So, I understand from you that client call returns after updating the >> commit log and updates to memtables are async after that - with >> how-much-ever short a delay tried by Cassandra? >> >> And the reads are always off memtables? >> >> So, theoretically, there is a possibility of a read missing a write >> because it has not come to memtables from the commit log yet? >> >> Is there anything that I can tell about my configuration that would help? >> > >
