I don't know enough about MongoDB to answer your question, and it sounds like you didn't know enough about it to even consider putting it into production for th

I don't know enough about MongoDB to answer your question, and it sounds like you didn't know enough about it to even consider putting it into production for this project. That's where you got screwed. Trying out new technology when you have a likely impossible deadline and then having it fall over in miserable fashion for everyone to see is a good way to get fired. At that point, the debate is not over the ridiculous constraints placed upon you, but rather over the decisions you made. http://www.mongodb.org/display/DOCS/Connections http://www.mongodb.org/display/DOCS/Connections That page says each connection spawns a thread. That could be a good lead. The documentation suggests using a connection pool (although many drivers will do this automatically). Were you using one? http://stackoverflow.com/questions/8439639/mongodb-max-connections http://stackoverflow.com/questions/8439639/mongodb-max-conne... That StackOverflow question is about supporting 20k concurrent users. It could also be a matter of insufficient hardware. I don't know, but I would start looking at what kind of performance can be expected in different setups and go from there. The most important thing is to properly test your setup. Prepare for a process of trial and error and expect it to take some time.