Problemas with process escalator and housekeeper

[basartak]

Hello

I have a zabbix monitoring system with problems when execute this actions (send messages witch delay)
- Send mail to users (2000 per user per day)
- Send events to others monitoring systems (500 per day)

I see the process scalator working all time (90% of the time).

When I stop the housekeepeer the process scalator work fine but when restart housekeepeer return the problems
if I stop the housekeepeer the mysql database grown more than others days.

my system consists in

3 servers
1 zabbix server
1 zabbix proxy + GUI
1 MySQL database

Number of hosts (monitored/not monitored/templates) 1829 1704 / 13 / 112
Number of items (monitored/disabled/not supported) 227266 22433 / 203903 / 930
Number of triggers (enabled/disabled) [problem/ok] 12637 11665 / 972 [302 / 11363]
Required server performance, new values per second 360.31 -

How can i tunning the system for solve this problem?

thanks