A repop is a sub-operation between primaries and replicas mostly.

That op only shows a duration of 1.3 seconds and the delay you
mentioned previously was under a second. Do you see larger delays? Are
they always between "sub_op_committed" and "commit_sent"?

What is your workload and how heavily utilised is your
cluster/network? How hard are the underlying disks working?

On Thu, Mar 21, 2019 at 4:11 PM Glen Baars <[email protected]> wrote:
>
> Hello Brad,
>
> It doesn't seem to be a set of OSDs, the cluster has 160ish OSDs over 9 hosts.
>
> I seem to get a lot of these ops also that don't show a client.
>
>             "description": "osd_repop(client.14349712.0:4866968 15.36 
> e30675/22264 15:6dd17247:::rbd_data.2359ef6b8b4567.000000000042766
> a:head v 30675'5522366)",
>             "initiated_at": "2019-03-21 16:51:56.862447",
>             "age": 376.527241,
>             "duration": 1.331278,
>
> Kind regards,
> Glen Baars
>
> -----Original Message-----
> From: Brad Hubbard <[email protected]>
> Sent: Thursday, 21 March 2019 1:43 PM
> To: Glen Baars <[email protected]>
> Cc: [email protected]
> Subject: Re: [ceph-users] Slow OPS
>
> Actually, the lag is between "sub_op_committed" and "commit_sent". Is there 
> any pattern to these slow requests? Do they involve the same osd, or set of 
> osds?
>
> On Thu, Mar 21, 2019 at 3:37 PM Brad Hubbard <[email protected]> wrote:
> >
> > On Thu, Mar 21, 2019 at 3:20 PM Glen Baars <[email protected]> 
> > wrote:
> > >
> > > Thanks for that - we seem to be experiencing the wait in this section of 
> > > the ops.
> > >
> > >                     {
> > >                         "time": "2019-03-21 14:12:42.830191",
> > >                         "event": "sub_op_committed"
> > >                     },
> > >                     {
> > >                         "time": "2019-03-21 14:12:43.699872",
> > >                         "event": "commit_sent"
> > >                     },
> > >
> > > Does anyone know what that section is waiting for?
> >
> > Hi Glen,
> >
> > These are documented, to some extent, here.
> >
> > http://docs.ceph.com/docs/master/rados/troubleshooting/troubleshooting
> > -osd/
> >
> > It looks like it may be taking a long time to communicate the commit
> > message back to the client? Are these slow ops always the same client?
> >
> > >
> > > Kind regards,
> > > Glen Baars
> > >
> > > -----Original Message-----
> > > From: Brad Hubbard <[email protected]>
> > > Sent: Thursday, 21 March 2019 8:23 AM
> > > To: Glen Baars <[email protected]>
> > > Cc: [email protected]
> > > Subject: Re: [ceph-users] Slow OPS
> > >
> > > On Thu, Mar 21, 2019 at 12:11 AM Glen Baars <[email protected]> 
> > > wrote:
> > > >
> > > > Hello Ceph Users,
> > > >
> > > >
> > > >
> > > > Does anyone know what the flag point ‘Started’ is? Is that ceph osd 
> > > > daemon waiting on the disk subsystem?
> > >
> > > This is set by "mark_started()" and is roughly set when the pg starts 
> > > processing the op. Might want to capture dump_historic_ops output after 
> > > the op completes.
> > >
> > > >
> > > >
> > > >
> > > > Ceph 13.2.4 on centos 7.5
> > > >
> > > >
> > > >
> > > >             "description": "osd_op(client.1411875.0:422573570
> > > > 5.18ds0
> > > > 5:b1ed18e5:::rbd_data.6.cf7f46b8b4567.000000000046e41a:head [read
> > > >
> > > > 1703936~16384] snapc 0=[] ondisk+read+known_if_redirected
> > > > e30622)",
> > > >
> > > >             "initiated_at": "2019-03-21 01:04:40.598438",
> > > >
> > > >             "age": 11.340626,
> > > >
> > > >             "duration": 11.342846,
> > > >
> > > >             "type_data": {
> > > >
> > > >                 "flag_point": "started",
> > > >
> > > >                 "client_info": {
> > > >
> > > >                     "client": "client.1411875",
> > > >
> > > >                     "client_addr": "10.4.37.45:0/627562602",
> > > >
> > > >                     "tid": 422573570
> > > >
> > > >                 },
> > > >
> > > >                 "events": [
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598438",
> > > >
> > > >                         "event": "initiated"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598438",
> > > >
> > > >                         "event": "header_read"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598439",
> > > >
> > > >                         "event": "throttled"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598450",
> > > >
> > > >                         "event": "all_read"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598499",
> > > >
> > > >                         "event": "dispatched"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598504",
> > > >
> > > >                         "event": "queued_for_pg"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598883",
> > > >
> > > >                         "event": "reached_pg"
> > > >
> > > >                     },
> > > >
> > > >                     {
> > > >
> > > >                         "time": "2019-03-21 01:04:40.598905",
> > > >
> > > >                         "event": "started"
> > > >
> > > >                     }
> > > >
> > > >                 ]
> > > >
> > > >             }
> > > >
> > > >         }
> > > >
> > > >     ],
> > > >
> > > >
> > > >
> > > > Glen
> > > >
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> > >
> > >
> > >
> > > --
> > > Cheers,
> > > Brad
> > > This e-mail is intended solely for the benefit of the addressee(s) and 
> > > any other named recipient. It is confidential and may contain legally 
> > > privileged or confidential information. If you are not the recipient, any 
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> >
> >
> >
> > --
> > Cheers,
> > Brad
>
>
>
> --
> Cheers,
> Brad
> This e-mail is intended solely for the benefit of the addressee(s) and any 
> other named recipient. It is confidential and may contain legally privileged 
> or confidential information. If you are not the recipient, any use, 
> distribution, disclosure or copying of this e-mail is prohibited. The 
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-- 
Cheers,
Brad
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