Sylvain, here is my ticket, but I guess you already know it since you are the assignee :) -->https://issues.apache.org/jira/browse/CASSANDRA-3465 Riyad, Thanks for your help.
Alain 2011/11/7 Riyad Kalla <rka...@gmail.com> > Alain thank you for all the clarification, I understand exactly what you > meant now... and as a result am just as confused as you are :) > > What version of Cassandra are you using? Can you share the important parts > of your config? (you double checked that your replication factor is set on > all 3 to "3"?) > > Also out of curiosity, if you keep querying for up to 5 mins (say every 10 > seconds) do counter1, 2 and 3 still show the same wrong values for getValue > or do the values eventually converge on the correct amounts? > > (I assume 5mins is a long enough window to test, maybe I'm wrong and > another Cassandra dev can correct me here). > > -R > > > On Mon, Nov 7, 2011 at 9:57 AM, Alain RODRIGUEZ <arodr...@gmail.com>wrote: > >> I retried it after restarting all the servers. >> >> I still have wrong results (I simulated an event 5 times and it was >> counted 3 times by some counters 4 or 5 times by others. >> >> What I meant by "but now every request returns me always the same count >> value..." will be easier to explain with an example : >> >> event 1: >> >> counter1.increment >> counter2.increment >> counter3.increment >> >> . >> . >> . >> >> event 5: >> >> counter1.increment >> counter2.increment >> counter3.increment >> >> Show results : >> >> counter1.getValue = returns 4 >> counter2.getValue = returns 3 >> counter3.getValue = returns 5 >> >> counter1.getValue = returns 5 >> counter2.getValue = returns 3 >> counter3.getValue = returns 5 >> >> counter1.getValue = returns 4 >> counter2.getValue = returns 4 >> counter3.getValue = returns 5 >> >> ... >> >> So I've got wrong values, and not always the same ones. In my previous >> email I tried to tell you by saying "but now every request returns me >> always the same count value..." that I had all the time the same wrong >> values, let us say : >> >> counter1.getValue = returns 4 >> counter2.getValue = returns 3 >> counter3.getValue = returns 5 >> >> counter1.getValue = returns 4 >> counter2.getValue = returns 3 >> counter3.getValue = returns 5 >> >> counter1.getValue = returns 4 >> counter2.getValue = returns 3 >> counter3.getValue = returns 5 >> >> But that is not true, I still have some "random" wrong values, maybe >> haven't I query to get counter values often enough to see it last time. >> >> Sorry of not being clearer, that is not easy to explain, neither to >> understand for me. >> >> Thanks for help. >> >> Alain >> >> >> 2011/11/7 Riyad Kalla <rka...@gmail.com> >> >>> Alain, >>> >>> When you tried CL.All was that only after you had made the change of >>> ReplicationFactor=3 and restarted all the servers? >>> >>> If you hadn't restarted the servers with the new RF, I am not sure that >>> CL.All would have the intended effect. >>> >>> Also, I wasn't sure what you meant by "but know every request returns me >>> always the same count value..." -- didn't want the requests to always >>> return you the same values? >>> >>> Or maybe you are saying that it always returns the same *wrong* value? >>> Like you do: >>> >>> counter.increment (v=1) >>> counter.increment (v=2) >>> counter.increment (v=3) >>> >>> counter.getValue = returns 7 >>> counter.getValue = returns 7 >>> counter.getValue = returns 7 >>> >>> or something inconsistent like that? >>> >>> On Mon, Nov 7, 2011 at 9:09 AM, Alain RODRIGUEZ <arodr...@gmail.com>wrote: >>> >>>> I've tried with CL.All, but it doesn't wotk better. I still have >>>> strange values (between 4 and 10 events counted instead of 10) but know >>>> every request returns me always the same count value... >>>> >>>> It's very strange. >>>> >>>> Any other idea ? >>>> >>>> Alain >>>> >>>> >>>> 2011/11/7 Riyad Kalla <rka...@gmail.com> >>>> >>>>> Alain, >>>>> >>>>> Try using a CL of 3 or "ALL" and see if that the problem goes away. >>>>> >>>>> Your replication factor (as I just learned) dictates how many nodes >>>>> each piece of data is replicated to; by using a RF of 3 you are saying >>>>> "replicate all my data to all my nodes" (in this case counters). >>>>> >>>>> This doesn't happen immediately, but you can *force* it to happen on >>>>> write by specifying a CL of "ALL". If you specify "1" then your counter >>>>> value is written to one member of the ring, then your command returns. >>>>> >>>>> If you keep querying you will bounce around your ring, reading the >>>>> values from the different nodes until a future date at *which point* all >>>>> the values will likely agree. >>>>> >>>>> If you keep all your code you have now exactly the same, just change >>>>> the code at the end where you read the counter value back, to keep reading >>>>> the counter value back every second for 60 seconds and see if all the >>>>> values eventually match up -- they should (as the counter value is >>>>> replicated to all the nodes and their old values discarded). >>>>> >>>>> -R >>>>> >>>>> >>>>> On Mon, Nov 7, 2011 at 8:15 AM, Alain RODRIGUEZ <arodr...@gmail.com>wrote: >>>>> >>>>>> Hi, >>>>>> >>>>>> I trying to switch from a RF = 1 to a RF = 3, but I get wrong values >>>>>> from counters when doing so... >>>>>> >>>>>> I got a CF that contains many counters of some events. When I'm at RF >>>>>> = 1 and simulate 10 events, they are well counted. >>>>>> However, when I switch to a RF = 3, my counter show a wrong value >>>>>> that sometimes change when requested twice (it can return 7, then 5 >>>>>> instead >>>>>> of 10 all the time). >>>>>> >>>>>> I first thought that it was a problem of CL because I seem to >>>>>> remember that I read once that I had to use CL.One for reads and writes >>>>>> with counters. So I tried with CL.One, without success... >>>>>> >>>>>> What am I doing wrong ? Is that some precaution to take when >>>>>> replicating counters ? >>>>>> >>>>>> Alain >>>>>> >>>>> >>>>> >>>> >>> >> >
