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From Philippe <watche...@gmail.com>
Subject Re: Dropped messages
Date Sun, 07 Aug 2011 21:00:25 GMT
Thanks Aaron.
The first paragraph is very clear however the 2nd paragraph leaves me
wondering regarding counter columns in my setup.

I am writing at CL.ALL and reading at CL.ONE so if I get dropped messages,
it will show up as Timeouts on the client side so possibly the mutation was
not run on all nodes. Then when I come in reading at CL.ONE on any of the
nodes (before the daily nodetool repair), I will get out of date data if the
read_repair chance is < 1 right ? That's what I made out of the thread from
my previous question.

So basically, I am wondering if it makes any sense at all to have a
CL.ALL/CL.ONE setup in the hope of maximizing read performance since
i) I have to have the read repair chance percentage at 100% if I want
consistency and I still take the hypothetical performance hit on write (of
having to wait for every replica to respond)
ii) if I set the read repair chance to <100% then I may get inconsistent
data


2011/8/7 aaron morton <aaron@thelastpickle.com>

> Just added this to the wiki
>
> http://wiki.apache.org/cassandra/FAQ#dropped_messages
>
> Cheers
>
> -----------------
> Aaron Morton
> Freelance Cassandra Developer
> @aaronmorton
> http://www.thelastpickle.com
>
> On 6 Aug 2011, at 10:53, Philippe wrote:
>
> Hi,
> I see lines like this in my log file
>  INFO [ScheduledTasks:1] 2011-08-06 00:51:57,650 MessagingService.java
> (line 586) 358 MUTATION messages dropped in server lifetime
>  INFO [ScheduledTasks:1] 2011-08-06 00:51:57,658 MessagingService.java
> (line 586) 297 READ messages dropped in server lifetime
>  INFO [ScheduledTasks:1] 2011-08-06 00:51:57,658 MessagingService.java
> (line 586) 4696 RANGE_SLICE messages dropped in server lifetime
>
> How worried should I be ?
> Are they reported as timeout exceptions on the client ?
>
> Thanks
>
>
>

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