How to determine cpu ram needed for rails application?

Question

What is the most accurate way to determine the number of processor and ram speeds needed to run my rails application?

I believe there are stress testing tools like Tsung , but how can I determine, for example, that I need X more ram, or X more processor? I would like to find a way to roughly measure application performance so that I can anticipate future needs. I think this data will also be useful for me to decide whether to upgrade one machine or get another dedicated machine and put all the databases on it.

Essentially, I am concerned about the problems of scaling and how to predict them. Thank you in advance!

Answer 1

Do you have command line access for machines running your application? An easy way to get this information is to use it top, assuming it's a NIX based machine.

top not as sophisticated as special monitoring tools, but will allow you to view the current processor, memory usage, etc.

Answer 2

Heroku Engine Yard . , , , , ( ), ..

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