Cephalocon 2023

One of the new features in the Reef release is the introduction of a new read 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 read load on all OSDs was never handled. This proves to be a performance problem, especially in small clusters and in pools with less PGs. In this presentation, I will discuss the difference between capacity balancing and read balancing, explain what was accomplished for Reef, and outline future plans to further improve the Ceph balancing process. This presentation features updated developments on the read balancer that go beyond the "proof of concept" that was shown in Ceph Virtual 2022.