On Tue, Nov 27, 2018 at 10:04 AM Yiming Zhang <yzhan298@xxxxxxxx> wrote: > > Hi All, > > I’m trying to understand the throttlers in Ceph, and I may need suggestions from the community. > I plan to run some experiments against the throttler in the BlueStore to measure the latency performance. > The parameters of interest include: > > bluestore_throttle_bytes > bluestore_throttle_deferred_bytes > bluestore_throttle_cost_per_io > bluestore_throttle_cost_per_io_hdd > bluestore_throttle_cost_per_io_ssd > > I’ll change these parameter and workload(size, type) to measure latency over time. The goal is to > Propose a new throttler that can Keep as few operations in the BlueStore work queue as possible > without increasing latency. > > Is this the right direction to go? > Is there internal classifications for requests(onode, omap, collection obj, data blob) to be throttled in ObjectStore layer? I think you'll want to be careful how you construct the test, because it seems like there is throttling / limits imposed at the bluestore level, client level[, and probably in the OSD itself somewhere]. Are you planning on testing BlueStore directly, or generating a workload at the rados client level?
