[imp] Horde/IMP performance and system requirements (50k+ accounts)

[Janne Peltonen]

Thanks for your answers. A couple comments:

On Fri, Mar 20, 2009 at 09:53:49AM +0100, LALOT Dominique wrote:
> They notice that there is a big difference on the fact we are using dimp
> (much more little get).
> 
> What you can do, is lock the prefs initial_application and use IMP instead
> of DIMP.

We've already done that (partly because our users got very confused with
DIMP).

> Another point is alarms.php or reminders.php. I noticed during my
> tests that:
> reminders.php should be avoided (If you leave it in crontab every 5', it's a
> mistake). Jan said it was just for daily summary. As I locked that, only
> alarms.php is necessary. But alarms.php also can be a problem, as it runs
> every 5 minutes and generates tons of selects. Don't remember exactly but
> more than 10k for 4k users.

So they do. As we've disabled Kronolith completely, we've also disabled
both alarms and reminders.

On the other hand, there was the one server with Kronolith & co.
enabled, but I don't seem to find these scripts in any crontabs there,
either. And I don't remember installing them manually anywhere, either,
so they shouldn't be doing anything (can't see them in the process list,
at any time, either).

> Also, you'll have to look at mysql. For big databases, you need special
> tuning as default values are not good. We are in he way to put (for HA)
> another mysql server and we will split the access to several servers.
> (replica)

There was a way to do that? I know that you can create an
active-passive replica system with MySQL, but didn't know that there's
an active-active option.

> As I reread your mail, look at your SQL setup..

There has been much tweaking in there, we read through all possible
documents abt increasing mysql performance... The mytop util was also of
much help.

--clip--
[mysqld]
#port=3307
#innodb_force_recovery = 6

datadir=/db/mysql
socket=/var/lib/mysql/mysql.sock
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

#enough connections for all three webmail servers
set-variable = max_connections=1200
#default:10, would create trouble
set-variable = max_connect_errors=10000
set-variable = log_warnings=2     

#new memory parametres -vviitane 27.8.2008
set-variable = table_cache=3600
#  vmk/jmp 09.10.2008 lowered the value because of memory trouble
#set-variable = sort_buffer=128M
set-variable = sort_buffer=32M
# vmk/jmp 08.10.2008 lowered the value because of memory trouble
#set-variable = key_buffer=1024M
set-variable = key_buffer=256M
set-variable = join_buffer=128M
set-variable = max_allowed_packet=16M
set-variable = query_cache_size=512M
set-variable = tmp_table_size=256M

innodb_file_per_table
innodb_buffer_pool_size = 1024M

[mysql.server]
user=mysql
basedir=/var/lib

[mysqld_safe]
err-log=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
--clip--

Almost all tables are InnoDB.


--Janne
-- 
Janne Peltonen <janne.peltonen at helsinki.fi> PGP Key ID: 0x9CFAC88B
Please consider membership of the Hospitality Club (http://www.hospitalityclub.org)