Hi André, I am just a user of cassandra and did not look into the code deeply.
However, my guess is that cassandra only guarantee that if you successfully write and you successfully read, then quorum will give you the latest data. not finding the just inserted data may be due to the failure of successfully write or the failure of successfully read. if it is the failure of successfully write, then pycassa should give you some error message. if it is the failure of successfully read, then pycassa may give you timeout error or not-found error. To test it fairly, it is better to setup the scenario as continuously write/read same key/column name, but with different column value. Then you should be able to see that when you read, either you read the latest data (successful write/read), or you read the old data (fail write/success read), or you read nothing (fail read) Hopefully my guess is on the right track, and hopefully you understand what I mean. Sincerely, Hsiao On Mon, Mar 11, 2013 at 12:00 AM, André Cruz <andre.c...@co.sapo.pt> wrote: > Hello. > > In my application it sometimes happens that I execute a multiget (I use > pycassa) to fetch data that I have just inserted. I use quorum writes and > reads, and my RF is 3. > > I've noticed that sometimes (1 in 1000 perhaps) an insert followed (300ms > after) by a multiget will not find the just inserted data. Is this normal? Or > is something wrong? Can there be some delay to obtain the inserted data even > with quorum? > > Best regards, > André
