Do you have any ideas, advices on how to investigate in more details? 

What sort of read queries are you sending ?
Are you using large multi gets ? 
Are these servers under IO load ? / Is there a lot of compaction going on ?

Cheers


-----------------
Aaron Morton
Freelance Developer
@aaronmorton

On 3/07/2012, at 3:59 AM, Olivier Mallassi wrote:

Thanks for the answer. In fact this is maybe simpler. 

We do a lot of inserts and a couple of reads. 
- tpstats show us the pending read stage was growing. 
It seems there was an issue with one of our request. We have 4 indexed columns (UT8Type) 
First, one of the indexed value was "-----------". we replaced this value by and empty string and it works better. (running the query in CLI)

Yet, we still observed pending Read Stage after 10 minutes of run (on a couple of nodes). 

Do you have any ideas, advices on how to investigate in more details? 

Any help would be appreciate. 


On Sun, Jul 1, 2012 at 8:56 AM, Jonathan Ellis <jbellis@gmail.com> wrote:
Sounds like http://wiki.apache.org/cassandra/FAQ#ubuntu_ec2_hangs to me.

On Fri, Jun 29, 2012 at 1:45 AM, Olivier Mallassi <omallassi@octo.com> wrote:
> Hi all
>
> We have a 12 servers clusters (8 cores by machines..).
> OS is Ubuntu 10.04.2.
>
> On one of the machine (only one) and without any load (no inserts, no
> reads....), we have a huge CPU Load whereas there is no activities (no
> compaction in progress etc...)
> A top on the machine show us the process jscv is using all the available
> CPUs.
>
> Is that link to JNA? do you have any ideas?
>
> Cheers
>
> --
> ............................................................
> Olivier Mallassi
> OCTO Technology
> ............................................................
> 50, Avenue des Champs-Elysées
> 75008 Paris
>
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>



--
Jonathan Ellis
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support
http://www.datastax.com



--
............................................................
Olivier Mallassi
OCTO Technology
............................................................
50, Avenue des Champs-Elysées
75008 Paris

Mobile: (33) 6 28 70 26 61
Tél: (33) 1 58 56 10 00
Fax: (33) 1 58 56 10 01

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