The problem with Mongo's concurrency approach is that when you introduce writes to the equation (which take out an exclusive lock on the database), the system b

The problem with Mongo's concurrency approach is that when you introduce writes to the equation (which take out an exclusive lock on the database), the system becomes unusable. Here's a link to some of the benchmarking work I did. Ignoring the comparison to Clustrix, you can clearly see readers getting starved out when a writer does io. http://sergeitsar.blogspot.com/2011/01/mongodb-vs-clustrix-comparison-part-1.html http://sergeitsar.blogspot.com/2011/01/mongodb-vs-clustrix-c...