<p>I'm currently running mongrel clusters with monit watching over them for 8 Rails applications on one server.</p>

<p>I'd like to move 7 of these applications to mod_rails, with one remaining on mongrel. The 7 smaller applications are low-volume, while the one I'd like to remain on mongrel is a high volume, app.</p>

<p>As I understand it, this would be the best solution - as the setting PassengerPoolIdleTime only can be applied at a global level.</p>

<p>What configuration gotchas should I look out for with this type of setup?</p>

I would probably just move all the apps to mod_rails, as the performance seems comparable to Mongrel and there's less administration overhead.
With regards to configuration gotchas, just make sure that you allow your public directory, or you'll find static assets failing:
```
```
<Directory "/var/www/app/current/public">
    Options FollowSymLinks
    AllowOverride None
    Order allow,deny
    Allow from all
</Directory>
```
```
Aside from that, if you know how to configure Apache, mod_rails is very painless.