[LRUG] Server capacity

[Andrew Stewart]

Hola El Rug,

What sort of capacity do people run their servers at?

I have a Rails app on a 1-core Ubuntu 10.04 VPS with 1GB RAM.  Everything runs on that box: web server (Nginx), app servers (Unicorn with 5 workers), MySQL, background jobs etc etc.

The RAM usage hovers at around 75%.  I want to make the most of what I've got; is 75% too conservative?  Adding another Unicorn worker would take the RAM usage to about 85%.  I wonder how much memory it's sensible to use up.

Another thing: from time to time the app renders big PDFs with Prawn, and when this happens the CPU is maxed out for potentially several minutes, adversely affecting responsiveness.  What's a good way to address this?

Thanks in advance.  Sorry this isn't a job ad ;)

Cheers
Andy Stewart

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http://airbladesoftware.com