Being sort of performance engineer for the last couple of years, I can tell for sure that there's no free application that will do your work out of the box. It will take some time to write custom code, depending on your level of knowledge in programming languages. Personally I would recommend Perl's module Benchmark - it has suitable interface for such tasks. Certainly, just in case you have perl knowledge, but if you're going to work on it for a long time, it might worth investing in it. Also, another tool you can use is Sysbench, see its documentation for more details.