Re: [Sequoiadb-discuss] [Sequoia] Problems with sequoia in Loadtests

[Emmanuel C. <ma...@fr...>]

Hi Toni,

The Sequoia mailing list has moved to 
seq...@li....
> We are doing LoadTests of our product which is based in Sequoia + 
> mysql with 2 BE´s.
>  
> And the thing is that some SQL comands get stuck from time to time 
> spending more that 1seg to answer, I have donr a trace in MYSQL and 
> response in MYSQL is quite quickly ( 1mseg ). So, I suspect that we 
> have some problems in sequoia.
>  
> Is there any possiblity to traduce the messages from a TCPDUMP, in 
> order to see when sequoia response the the SQL sent from hibernate ?
>  
> We are working with jboss-4.0.3SP1, sequoia-2.10.10 and mysql 4.1.20 
> in a RHEL environment !
The delays you are observing might be due to retransmissions in the 
group communication. Are you using JGroups?

To sample the request arrival time, you can activate the following in 
log4j.properties:
# To trace requests #
log4j.logger.org.continuent.sequoia.controller.virtualdatabase.request=INFO, 
Requests
# To trace distributed requests #
log4j.logger.org.continuent.sequoia.controller.distributedvirtualdatabase.request=INFO, 
DistributedRequests

This will give you the request arrival time at each controller (look for 
the results in log/request.log and log/distributed_request.log).

For the request response time, the write request response times are 
logged in the recovery log. You can also use the SQLMonitoring element 
in your virtual database configuration file (look for more info in 
sequoia.dtd) to profile request execution time.

Hope this helps,
Emmanuel

-- 
Emmanuel Cecchet
FTO @ Frog Thinker 
Open Source Development & Consulting
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email: ma...@fr...
Skype: emmanuel_cecchet