This thesis studies the performances of data servers on multicores. More precisely, we focus on the scalability with the number of cores. First, we study the internals of an event-driven multicore runtime. We demonstrate that false sharing and inter-core communications hurt performances badly, and prevent applications from scaling. We then propose several optimisations to fix these issues. In a second part, we compare the multicore performances of three Webservers, each reprensentative of a programming model. We observe that the differences between each server's performances vary as the number of cores increases. We are able to pinpoint the cause of the scalability limitation observed. We present one approach and some perspectives to overcome this limit.
