MongoDB vs. Redis vs. Cassandra for a fast-write, temporary row storage solution

Question

I\'m building a system that tracks and verifies ad impressions and clicks. This means that there are a lot of insert commands (about 90/second average, peaking at 250) and some

Answer 1

Just found this: http://blog.axant.it/archives/236

Quoting the most interesting part:

This second graph is about Redis RPUSH vs Mongo $PUSH vs Mongo insert, and I find this graph to be really interesting. Up to 5000 entries mongodb $push is faster even when compared to Redis RPUSH, then it becames incredibly slow, probably the mongodb array type has linear insertion time and so it becomes slower and slower. mongodb might gain a bit of performances by exposing a constant time insertion list type, but even with the linear time array type (which can guarantee constant time look-up) it has its applications for small sets of data.

I guess everything depends at least on data type and volume. Best advice probably would be to benchmark on your typical dataset and see yourself.