Optimize Node.js memory consumption

Question

I'm writing a simple cms in Node.js, Express and MongoDB. I'm planning to run a different Node.js process for every site. The problem is that after startup the process takes about 90m of RAM and for me it's too big (eight site take all server RAM). This memory is taken after the first connection to the site and other connections don't affect the memory.

Is there a guideline or a list of "best practices" to optimize this memory usage? I'm trying to track where the memory is allocated with process.memoryUsage() or a similar function but it's not simple to do this.

Is not a problem of memory leaks or something similar because the memory usage doesn't grow up after the first connection, so probably the optimization could be in loading less modules or do something differently...

Solution

The links below may help you to understand and detect memory leaks (if they do exist):

Debugging memory leaks in node.js

Detecting Memory Leaks in Node.js Applications

Tracking Down Memory Leaks in Node.js

These SO questions may also be useful:

How to monitor the memory usage of Node.js?

Node.js Memory Leak Hunting