Cephalocon 2022

One of the new features in the Quincy release is the introduction of a new workload balancer (aka primary balancer). While capacity balancing exists and works well since the introduction of the upmap balancer, the issue of primary balancing in order to even the load on all the OSDs was never handled. This proves to be a performance problem, especially in small clusters and in pools with less PGs. In this presentation we will discuss the difference (and sometimes the contradiction) between capacity balancing and workload balancing, explain what we did for Quincy, and outline future plans to further improve the Ceph balancing process.