[SOLVED] Best practice: Multiple django applications on a single Amazon EC2 instance

Issue

I've been runnning a single django application on Amazon EC2 using gunicorn to serve the django portion and nginx for the static files.

I'm going to be starting new project soon, and wondering which of the following options would be better:

1. A larger amazon EC2 instance (Medium) runnning multiple django applications
2. Multiple smallers EC2 instances (Small/Micro) all running their own django applications?

Would anybody have any experience with this? What would the relevant performance metrics I could measure to get a good cost to performance ratio?

Solution

The answer to this question really depends on your app I'm afraid. You need to benchmark to be sure you are running on the right instance type. Some key metrics to watch are:

• CPU
• Memory usage
• Requests per second, per instance size
• App startup time

You will also need to tweak nginx/gunicorn settings to make sure you are running with a configuration that is optimised for your instance size.

If costs are a factor for you, one interesting metric is "cost per ten thousand requests", i.e. how much are you paying per 10000 requests for each instance type?

Answered By - Mike Ryan