LinuxCon + ContainerCon North America 2016

As the number of cores and logical processors available in a single machine keeps growing, changing your programming model to match our new reality gets more important day by day.Scylla is a highly scalable NoSQL Database that uses the Seastar share-nothing / thread-per-core C++14 framework to achieve linear scalability with the number of cores in the machine. However, to achieve this level of scalability some functionality that are present in the Operating System had to be rewritten and moved to userspace. In some others, the Operating System had to be bypassed. As an example, the Seastar framework includes its own task-scheduler, memory allocator, and even an I/O scheduler. Using Seastar as an example, this talk will discuss the relationship between a highly scalable application and Linux. What makes sense to be done in userspace, and what is done so due to current shortcomings ?