I have confirmed this in production, with the default max-entries.
I have a bucket that I'm no longer writing to. Radosgw-agent had
stopped replicating this bucket. radosgw-admin bucket stats shows that
the slave is missing ~600k objects.
I uploaded a 1 byte file to the bucket. On the next pass, radosgw-agent
replicated 1000 entries.
I'm uploading and deleting the same file every 5 minutes. I'm using
more inter-colo bandwidth now. This bucket is catching up, slowly.
For now, I'm going to graph the delta of the total number of objects in
both clusters. If the slave is higher, it's catching up. If it's
lower, it's falling behind.
*Craig Lewis*
Senior Systems Engineer
Office +1.714.602.1309
Email cle...@centraldesktop.com <mailto:cle...@centraldesktop.com>
*Central Desktop. Work together in ways you never thought possible.*
Connect with us Website <http://www.centraldesktop.com/> | Twitter
<http://www.twitter.com/centraldesktop> | Facebook
<http://www.facebook.com/CentralDesktop> | LinkedIn
<http://www.linkedin.com/groups?gid=147417> | Blog
<http://cdblog.centraldesktop.com/>
On 2/6/14 18:32 , Craig Lewis wrote:
On 2/4/14 17:06 , Craig Lewis wrote:
Now that I've started seeing missing objects, I'm not able to
download objects that should be on the slave if replication is up to
date. Either it's not up to date, or it's skipping objects every pass.
Using my --max-entries fix
(https://github.com/ceph/radosgw-agent/pull/8), I think I see what's
happening.
Shut down replication
Upload 6 objects to an empty bucket on the master:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test2.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test3.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test4.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test5.jpg
None show on the slave, because replication is down.
Start radosgw-agent --max-entries=2 (1 doesn't seem to replicate anything)
Check contents of slave after pass #1:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
Check contents of slave after pass #10:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
Leave replication running
Upload 1 object, test6.jpg, to the master. Check the master:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test2.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test3.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test4.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test5.jpg
2014-02-07 02:06 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test6.jpg
Check contents of slave after next pass:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
Upload another file, test7.jpg, to the master:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test2.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test3.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test4.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test5.jpg
2014-02-07 02:06 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test6.jpg
2014-02-07 02:08 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test7.jpg
The slave doesn't get it this time:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
Upload another file, test8.jpg, to the master:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test2.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test3.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test4.jpg
2014-02-07 02:03 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test5.jpg
2014-02-07 02:06 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test6.jpg
2014-02-07 02:08 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test7.jpg
2014-02-07 02:10 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test8.jpg
The slave gets the 3rd file:
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test0.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test1.jpg
2014-02-07 02:02 10k dc5674336e2212a0819b7abcb811e323
s3://bucket1/test2.jpg
So I think the problem is caused by the shard marker being set to the
current marker after every pass, even if the bucket replication caps
on max-entries.
Updating the shard marker by uploading a file causes another pass on
the bucket, and the bucket marker is being tracked correctly.
I would prefer to track the shard marker better, but I don't see any
way to get the last shard marker given the last bucket entry. If I
track the shard marker correctly, then the stats I'm generating are
still somewhat useful (if incomplete). I'll be able to see when
replication falls behind because the graphs keep growing.
The alternative is to change the bucket sync so that it loops until
it's replicated everything up to the shard marker. In this case, I'll
be able to see that replication is falling behind because each pass
takes longer and longer to complete.
What do you guys think?
Either way, I believe all my data is waiting to be replicated. I just
need to fix this issue, and upload another object to every bucket
that's behind.
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
_______________________________________________
ceph-users mailing list
ceph-users@lists.ceph.com
http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
