Developers of Sympa

[Olivier Salaun <address@concealed>]

Petr Prazak wrote:

> O Salaun wrote :
> > You should first check mysql log file to find out what SQL queries
> > are performed by Sympa. Then try running them using mysql client
> > to find out which ones are critical.
> 
> It queries the database for a user;
> 
> mysql> EXPLAIN SELECT lower(email_user) AS email, gecos_user AS gecos,
> password_user AS password, cookie_delay_user AS cookie_delay,
> lang_user AS lang FROM user_table WHERE lower(email_user) = 
> 'address@concealed';
> [...]
> This query took 4 seconds.
> 
> I tried to remove the lower() from where clause:
> [...]
> This query took 0.01 seconds.
> 
> I see then it would be much better to store the email addresses as 
> lowecased.

That's a great optimization.
Actually Sympa lowercases email addresses before adding entries to DB,
but
we kept this for compatibility reason (users previously added).

Considering the performance you present (I also verified it on our
server),
we will delete the lower() from SQL query. 
Maybe we should provide a script to lowercase existing databases.

> But this doesn't explain what the wwsympa hangs when fetching a page 
> /wws/lists
> [...]
> Is there a way how to debug the wwsympa.fcgi to see what this process
> does so long ??

Not much, because running with FastCGI make it impossible to read
STDERR.
You should try running WWSympa without fastCGI to get error messages
in Apache error log.

> I have also raised the number of fastcgi processes to 25 from 5, to se
> if it helps (doesn't seem so).

I recommend you keep a low number of fastCGI servers ; each of them
comsumes 
your RAM.

--
Olivier Salaün
Comité Réseau des Universités