i am curious about how mongodb will perform in a limited vps. specifically, i'll deploy this configuration on 32-bit ubuntu 9.04 server with 128Mb memory (UPDATE: now i'm considering 360mb too).

• nginx and redis
• three instances of tornado apps (one is for mobile site; limited app, not my primary audience); has around 8 Collections. social webapp for my community.
• mongodb

all beside mongodb seems to have small footprint. memory-mapping-wise, i dont know how mongodb will behave.

i know it's a little bit a stretch to use this kind of config on a tiny vps, but that's what i can afford for now. i expect to have.. hmm.. maybe ~50 15rps. i did my homework doing a lot of frontend optimizations and yslow says grade A 91 (ruleset V2) :-)

anyone willing to share experiences? eg. how big the data set size when mongo hit the ceiling, performance when mongo do a lot of disk IO, etc. thanks.

UPDATE: this is my pet project. i'll get back to you when i have next spare time to do same httperf in a vbox with exact spec. suggestion how to do stress testing welcomed. i'm new to this kind of stuff.