About memory consumed by each connection in ql.io/node.js

[Aaron Wang]

Here is a quote from http://www.ebaytechblog.com/2011/11/30/announcing-ql-io/:

We were able to tune a regular developer-quality Ubuntu workstation to handle more than 120,000 active connections per node.js process, with each connection consuming about 2k memory. 

Now, I'm wondering that what dose this mean exactly? 2k memory per connection in application level or system level?

In my test, with a 4GB Ubuntu server, we could hold about 360, 000 concurrent connections,  and the whole system has about 200M free memory left, node.js processes consume about 1GB RSS. That means 10k per connection in system level and 3k per connection in application level.

[shimonchayim]

How are you measuring the memory consumption top?

[Aaron Wang]

I used 'free -m' command to watch system memory usage and 'top' command to inspect node.js processes(cluster mode) RSS usage.