On Tue, 26 Jan 2016, Deneau, Tom wrote:
> And I assume when I see an op with a description like
> "MOSDECSubOpRead(3.23s1 305 ECSubRead..."
> that this is the reading of the second chunk in a k=2,m=1 erasure pool?
Yes (although you can't tell k and m from the pgid--only that it's shard
1).
sage
>
> -- Tom
>
>
> > -----Original Message-----
> > From: Deneau, Tom
> > Sent: Monday, January 25, 2016 4:54 PM
> > To: ceph-devel@xxxxxxxxxxxxxxx
> > Cc: cbt@xxxxxxxxxxxxxx
> > Subject: historic ops showing up on unexpected osds
> >
> > I was looking at a performance discrepancy with reading objects
> > and I was looking at some historic ops and noticed several like this.
> > This is an erasure pool with k=2, m=1 so 3 chunks for each object.
> >
> > When I look at the pg mapping for this object shown below on this pool,
> > it is [12,14,6].
> > And indeed when I look at the actual pieces on disk, they are on the disks
> > that map to osds 12, 14, and 6.
> >
> > Yet this osd for which this particular historic op showed up was osd 11.
> > And I have seen other historic ops mapped to this same pg, which showed up
> > for instance on osd 15.
> > Why would osd 11 or ods 15 be involved in this object at all?
> >
> > -- Tom
> >
> >
> > {
> > "description": "osd_op(client.13056.0:2691 0-ggggjbjm []
> > 3.a3ebd1b8 ack+read+known_if_redirected e305)",
> > "initiated_at": "2016-01-25 13:01:15.824133",
> > "age": 60.812474,
> > "duration": 8.913674,
> > "type_data": [
> > "started",
> > {
> > "client": "client.13056",
> > "tid": 2691
> > },
> > [
> > {
> > "time": "2016-01-25 13:01:15.824133",
> > "event": "initiated"
> > },
> > {
> > "time": "2016-01-25 13:01:15.824258",
> > "event": "queued_for_pg"
> > },
> > {
> > "time": "2016-01-25 13:01:23.056172",
> > "event": "reached_pg"
> > },
> > {
> > "time": "2016-01-25 13:01:23.082064",
> > "event": "started"
> > },
> > {
> > "time": "2016-01-25 13:01:24.737807",
> > "event": "done"
> > }
> > ]
> > ]
> > },
> --
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