# add the `Databases` key to `/system/config.php` that would look like this (maybe same database server can be used as slave too for testing purposes):
```
lang=php
$_CONFIG['Databases'] = array(
array(
'DBHost' => 'host_of_1st_slave',
'DBUser' => 'user_of_1st_slave',
'DBUserPassword' => 'password_of_1st_slave',
'DBLoad' => 1, // means 100% of slave load would go to this slave
),
);
```
# configure a separate database server with slave database and replication from master
# trigger some errror to create record in `System Log` section
# place a following code in any event, that you can trigger: `$this->Application->deleteLog(unique_id)` (replace `unique_id` with value from `LogUniqueId` column of any record in `System Log` section)
# confirm, that chosen record was removed from database