Well, maybe the situation is really bad, recently I came through some memory problems, So I did a lot of tests, I disabled the cache, also i disabled the sessions but memory problem continued. So I delegated this problem to Uwsgi. I had to set limit-as to 512. web2py/uwsgi memory usage grew very fast and when it gets 512MB uwsgi recycles the workers, also I needed to set reload-on-as and reload-on-rss to recycle individual workers. I tested the same app running on Apache and with Apache I had no problems, also SCGI had no problems, the problems only happened with uwsgi + nginx.
I figured out the perfect config[1], but note that this config is a workaround for uwsgi to reload its workers every time web2py hits the memory usage limit. As my application is not trivial (I used the model less approach and maybe I am having memory leaks on my own classes). With the correct uwsgi config my app is running very well. [1] https://github.com/web2py/web2py/pull/35 --