On Wed, 16 Sep 2015, GuangYang wrote:
> Hi Sam,
> As part of the effort to solve problems similar to issue #13104
> (http://tracker.ceph.com/issues/13104), do you think it is appropriate to add
> some parameters to pool setting:
> 1. recovery priority of the pool - we have a customized pool recovery
> priority (like process's nice value) to favor some pools over others. For
> example, the bucket index pool is usually much much smaller but important to
> recover first (e.g. might affect write latency as like issue #13104).
> 2. pool level recovery op priority - currently we have a low priority for
> recovery op (by default it is 10 while client io's priority is 63), is it
> possible to have a pool setting to customized the priority on pool level.
>
> The purpose is to give some flexibility in terms of favor some pools over
> others when doing recovery, in our case using radosgw, we would like to favor
> bucket index pool as that is on the write path for all requests.
I think this makes sense, and is analogous to
https://github.com/ceph/ceph/pull/5922
which does per-pool scrub settings. I think the only real question is
whether pg_pool_t is the right place to keep piling these parameters in,
or whether we want some unstructured key/value settings or something.
sage
