It seems it was linked to "data volume".
The symptoms were :
- a read query is executed on a server (#3 in our case). this query is like
select from CF where A= and B= and C= and D= where A..D are secondary
indexes.
- #3 CPU increased a lot (CPU load around 20 for 8 cores).
During that time, clust
> 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
@aaronmort
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 "---".
Sounds like http://wiki.apache.org/cassandra/FAQ#ubuntu_ec2_hangs to me.
On Fri, Jun 29, 2012 at 1:45 AM, Olivier Mallassi 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
>
precision : nmon does not show any IO (disk) activities
On Fri, Jun 29, 2012 at 8:45 AM, Olivier Mallassi 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 h
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
