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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: Counters and replication factor
Date Mon, 07 Nov 2011 16:09:00 GMT
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 <rkalla@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 <arodrime@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
>>
>
>

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