Locking in MongoDB for a Pintrest like website

Question

One of our client projects is a Pinterest like website. It was made with MySQL and CodeIgniter some time back. As they have recently gotten funding and hopefully will get a lot more traffic. We are rebuilding the website and are seriously considering MongoDB as it seems to be one of the more mature NoSQL DB with a big user base.

I know there were some concerns with global locking till version 2.2 post which they were taken care of.

This is my first project with mongodb and NoSQL. I have a question :

• Is the write lock still something that I should be worrying about?

Answer 1

My research in a few other places indicated that it isn't such a bad thing as it initially sounds like.

Video from 10gen talking about the global lock : http://www.youtube.com/watch?v=PIWVFUtBV1Q ( Skip to 55:00 for the global lock question )

Current version of mongodb : 2.4 -- Global lock removal happened in 2.2 Details: http://blog.serverdensity.com/goodbye-global-lock-mongodb-2-0-vs-2-2/

From watching a couple of other videos on it, the following statements sum up my current understanding of the issue :
"10gen rep : The global lock is something we are very serious about. The server wide lock is gone, now it is a database level lock and in the future we plan to make this to collection level.. "

"If the record you are trying to update is in the RAM, you will not notice the update because its so fast. It sounds really scary but, you shouldn't face too many issues because of this"