[prev in list] [next in list] [prev in thread] [next in thread] 

List:       ceph-users
Subject:    [ceph-users] Hammer to Jewel Upgrade - Extreme OSD Boot Time
From:       gfarnum () redhat ! com (Gregory Farnum)
Date:       2017-10-30 23:20:15
Message-ID: CAJ4mKGam7bvUrKY0dWKujSVVaE3Zb0m0MuJLX5X5-hRy75P=rQ () mail ! gmail ! com
[Download RAW message or body]

On Thu, Oct 26, 2017 at 11:33 AM Chris Jones <chris.jones at ctl.io> wrote:

> The long running functionality appears to be related to clear_temp_objects();
> from OSD.cc called from init().
>
>
> What is this functionality intended to do? Is it required to be run on
> every OSD startup? Any configuration settings that would help speed this up?
>
>
This function looks like it's cleaning up temporary objects that might have
been left behind. Basically, we are scanning through the objects looking
for temporaries, but we stop doing so once we hit a non-temp object
(implying they are ordered). So in the common case I think we're doing one
listing in each PG, finding there are no temp objects (or noting the few
that remain), and then advancing to the next PG. This will take a little
time as we're basically doing one metadata listing per PG, but that should
end quickly.

I'm curious why this is so slow for you as I'm not aware of anybody else
reporting such issues. I suspect the ZFS backend is behaving rather
differently than the others, or that you've changed the default config
options dramatically, so that your OSDs have to do a much larger listing in
order to return the sorted list the OSD interface requires.
-Greg
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20171030/f33d6eeb/attachment.html>

[prev in list] [next in list] [prev in thread] [next in thread]