On Jun 19, 2020, at 12:59 AM, qjpqzb(a)gmail.com wrote:
Hi,
I am trying to use CEPH dmclock to see how it works for QoS control. Especially, I want
to set “osd_op_queue” as “mclock_client” to config different [r, w, l] for each client.
The CEPH version I use is nautilus 14.2.9.
That feature was never fully realized and did not support setting reservation, weight, and
limit for each client. At best it simply kept a separate queue for each client so each
client’s tags would increment independently thereby promoting some “fairness" between
clients.
And as I look at master, it appears that the mclock scheduler was re-worked by Sam Just
and that feature is no longer there.
I noticed that in "OSD CONFIG REFERENCE"
section of CEPH documentation, it states that "the mClock based ClientQueue
(mclock_client) also incorporates the client identifier in order to promote fairness
between clients.", so I believe librados can support per-client configurations right
now. I wonder how I can set up the CEPH configuration to config different (r, w, l) for
different clients using such “client identifier"? Thanks.
I’d started an effort to allow client configuration via librados but needed to move onto
other rgw-centered tasks. Sam was looking at that code but I don’t know where he went with
it.
Best,
Eric