On Tue, Apr 26, 2016 at 10:37 AM, Abhishek Lekshmanan <abhishek@xxxxxxxx> wrote: > > Abhishek L writes: > >> Yehuda Sadeh-Weinraub writes: >> >>> On Mon, Apr 25, 2016 at 1:17 AM, Abhishek Lekshmanan <abhishek@xxxxxxxx> wrote: >>>> >>>> Yehuda Sadeh-Weinraub writes: >>>> >>>>> On Tue, Apr 19, 2016 at 11:08 AM, Yehuda Sadeh-Weinraub >>>>> <yehuda@xxxxxxxxxx> wrote: >>>>>> On Tue, Apr 19, 2016 at 10:54 AM, Abhishek L >>>>>> <abhishek.lekshmanan@xxxxxxxxx> wrote: >>>>>>> >>>>>>> Yehuda Sadeh-Weinraub writes: >>>>>>> >>>>>>>> On Tue, Apr 19, 2016 at 9:10 AM, Abhishek Lekshmanan <abhishek@xxxxxxxx> wrote: >>>>>>>>> Trying deleting objects & buckets from a secondary zone in a RGW >>>>>>>>> multisite configuration leads to some wierdness: >>>>>>>>> >>>>>>>>> 1. On deleting an object and the bucket immediately will mostly lead to >>>>>>>>> object and bucket getting deleted in the secondary zone, but since we >>>>>>>>> forward the bucket deletion to master only after we delete in secondary >>>>>>>>> it will fail with 409 (BucketNotEmpty) and gets reraised as a 500 to the >>>>>>>>> client. This _seems_ simple enough to fix if we forward the bucket >>>>>>>>> deletion request to master zone before attempting deletion locally, >>>>>>>>> (issue: http://tracker.ceph.com/issues/15540, possible fix: https://github.com/ceph/ceph/pull/8655) >>>>>>>>> >>>>>>>> >>>>>>>> Yeah, this looks good. We'll get it through testing. >>>>>>>> >>>>>>>>> 2. Deletion of objects themselves: deletion of objects themselves seems >>>>>>>>> to be a bit racy, deleting an object on a secondary zone succeeds, >>>>>>>>> listing the bucket seems to show an empty list, but gets populated with >>>>>>>>> the object again sometimes (this time with a newer timestamp), this is >>>>>>>>> not always guaranteed to be reproduce, but I've seen this often with >>>>>>>>> multipart uploads, as an eg: >>>>>>>>> >>>>>>>>> $ s3 -u list test-mp >>>>>>>>> Key Last Modified Size >>>>>>>>> -------------------------------------------------- -------------------- ----- >>>>>>>>> test.img 2016-04-19T13:00:17Z 40M >>>>>>>>> $ s3 -u delete test-mp/test.img >>>>>>>>> $ s3 -u list test-mp >>>>>>>>> Key Last Modified Size >>>>>>>>> -------------------------------------------------- -------------------- ----- >>>>>>>>> test.img 2016-04-19T13:00:45Z 40M >>>>>>>>> $ s3 -u delete test-mp/test.img # wait for a min >>>>>>>>> $ s3 -us list test-mp >>>>>>>>> -------------------------------------------------- -------------------- ----- >>>>>>>>> test.img 2016-04-19T13:01:52Z 40M >>>>>>>>> >>>>>>>>> >>>>>>>>> Mostly seeing log entries of this form in both the cases ie. where >>>>>>>>> delete object seems to be successfully delete in both master and >>>>>>>>> secondary zone and the case where it succeeds in master and fails in >>>>>>>>> secondary : >>>>>>>>> >>>>>>>>> 20 parsed entry: id=00000000027.27.2 iter->object=foo iter->instance= name=foo instance= ns= >>>>>>>>> 20 [inc sync] skipping object: dkr:d8e0ec3d-b3da-43f8-a99b-38a5b4941b6f.14113.2:-1/foo: non-complete operation >>>>>>>>> 20 parsed entry: id=00000000028.28.2 iter->object=foo iter->instance= name=foo instance= ns= >>>>>>>>> 20 [inc sync] skipping object: dkr:d8e0ec3d-b3da-43f8-a99b-38a5b4941b6f.14113.2:-1/foo: canceled operation >>>>>>>>> >>>>>>>>> Any ideas on this? >>>>>>>>> >>>>>>>> >>>>>>>> Do you have more than 2 zones syncing? Is it an object delete that >>>>>>>> came right after the object creation? >>>>>>> >>>>>>> Only 2 zones ie. one master and one secondary, req, on secondary. The delete came right after the >>>>>>> create though >>>>>> >>>>>> There are two issues that I see here. One is that we sync an object, >>>>>> but end up with different mtime than the object's source. The second >>>>>> issue is that we shouldn't have synced that object. >>>>>> >>>>>> There needs to be a check when syncing objects, to validate that we >>>>>> don't sync an object that originated from the current zone (by >>>>>> comparing the short zone id). We might be missing that. >>>>>> >>>>> >>>>> For the first issue, see: >>>>> https://github.com/ceph/ceph/pull/8685 >>>>> >>>>> However, create that follows by a delete will still be a problem, as >>>>> when we sync the object we check it against the source mtime is newer >>>>> than the destination mtime. This is problematic with deletes, as these >>>>> don't have mtime once the object is removed. I think the solution >>>>> would be by using temporary tombstone objects (we already have the olh >>>>> framework that can provide what we need), that we'll garbage collect. >>>> >>>> Further information from logs if it helps: >>>> >>>> 2016-04-19 17:00:45.539356 7fc99effd700 0 _send_request(): deleting obj=test-mp:test.img >>>> 2016-04-19 17:00:45.539902 7fc99effd700 20 _send_request(): skipping object removal obj=test-mp:test.img (obj mtime=2016-04-19 17:00:26.0.098255s, request timestamp=2016-04-19 17:00:17.0.395208s) >>>> >>>> This is what the master zone logs show, however the request timestamp >>>> logged here is the `If-Modified-Since` value from secondary zone when >>>> the actual object write was completed (and not the time when deletion >>>> was completed), do we set the value of the deletion time anywhere else >>>> in the BI log >>>> >>>> >>> >>> Did you apply PR 8685? >>> >>> Also, take a look at this: >>> >>> https://github.com/ceph/ceph/pull/8709 >>> >>> With the new code we do store the object creation time in the delete >>> bucket index entry. That way we make sure we only sync object removal, >>> if the object was the same or older than the one that was actually >>> removed. > > Applied both PRs atop of master + 8655, basically now the object doesn't > resync back to the secondary zone after deletion which we observed > before.A create followed by an immediate delete succeeds delete in both the > zones almost every time. > > However allowing the object to sync to primary by introducing a delay, > for eg a script on secondary like: > > for i in {1..20}; do s3 -us put foobar/foo$i filename=test.img && sleep 3 && s3 -us delete foobar/foo$i; done > > gives a empty list on the secondary zone, on the primary zone however it > looks like very few objects got actually deleted and others are still existing > > $ s3 -us list foobar > Content-Type: application/xml > Request-Id: tx000000000000000001db8-00571f9cdb-1015-us-east-1 > Content-Length: 4713 > Key Last Modified Size > -------------------------------------------------- -------------------- ----- > foo1 2016-04-26T14:24:25Z 87M > foo10 2016-04-26T14:27:28Z 87M > foo11 2016-04-26T14:27:50Z 87M > foo12 2016-04-26T14:28:12Z 87M > foo14 2016-04-26T14:28:48Z 87M > foo15 2016-04-26T14:29:09Z 87M > foo16 2016-04-26T14:29:30Z 87M > foo17 2016-04-26T14:29:51Z 87M > foo18 2016-04-26T14:30:12Z 87M > foo19 2016-04-26T14:30:33Z 87M > foo2 2016-04-26T14:24:47Z 87M > foo20 2016-04-26T14:30:54Z 87M > foo3 2016-04-26T14:25:07Z 87M > foo6 2016-04-26T14:26:05Z 87M > foo7 2016-04-26T14:26:24Z 87M > foo8 2016-04-26T14:26:47Z 87M > foo9 2016-04-26T14:27:07Z 87M > > Logs show this in case of failed deletes: > 2016-04-26 18:31:01.793673 7ff3f1ffb700 10 If-UnModified-Since: 2016-04-26 18:30:54.0.751623s Last-Modified: 0.000000 > 2016-04-26 18:31:01.793716 7ff3f1ffb700 20 _send_request(): delete_obj() obj=foobar3:foo20 returned ret=-2 > > In case of an object that succeeded deletion: > 2016-04-26 18:28:40.673885 7ff3f27fc700 10 If-UnModified-Since: 2016-04-26 18:28:30.0.510155s Last-Modified: 2016-04-26 18:28:30.510155 > > More interesting log: > 2016-04-26 18:25:52.660674 7ff3cf7fe700 10 If-UnModified-Since: 2016-04-26 18:25:46.0.700052s Last-Modified: 0.000000 > 2016-04-26 18:25:52.660698 7ff3cf7fe700 20 _send_request(): delete_obj() obj=foobar3:foo5 returned ret=-2 > ... > 2016-04-26 18:25:59.341420 7ff3a67fc700 10 If-UnModified-Since: 2016-04-26 18:25:46.0.700052s Last-Modified: 2016-04-26 18:25:46.700052 > [this was object foo5.. which was one of the objects that got deleted] > > Let me know if any other log info may be helpful (only debug rgw was > set, debug ms was 0) Yes, this would be great. If you could provide log with 'debug rgw = 20' and 'debug ms = 1' it'd be helpful. I'm trying to reproduce the issue, and was able to get some bad behavior, but different than what you describe. > > Possibly unrelated, a pkill radosgw sometimes used to throw an error > message with segfault, haven't seen this before though: > *** Caught signal (Segmentation fault) ** > in thread 7fdfbddfcb40 thread_name:radosgw > Do you have a backtrace? I found an issue that might explain this one, but need a backtrace to validate. Thanks, Yehuda > master sha1 before the patches was 25c2f5a793ff726facde236aa0c2dd78cf933c60 > > Regards > Abhishek >> >> Hadn't applied the PR yet, I'll apply both and see if I can reproduce >> the issue again. >>> >>> Yehuda >> >> Thanks >> -- >> Abhishek > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
