Re: Ceph strange issue after adding a cache OSD.

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I will try it, but I wanna see if it stays stable for a few days. Not
sure if I should report this bug or not.

On Thu, Nov 24, 2016 at 6:05 PM, Nick Fisk <nick@xxxxxxxxxx> wrote:
> Can you add them with different ID's, it won't look pretty but might get you out of this situation?
>
>> -----Original Message-----
>> From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Daznis
>> Sent: 24 November 2016 15:43
>> To: Nick Fisk <nick@xxxxxxxxxx>
>> Cc: ceph-users <ceph-users@xxxxxxxxxxxxxx>
>> Subject: Re:  Ceph strange issue after adding a cache OSD.
>>
>> Yes, unfortunately, it is. And the story still continues. I have noticed that only 4 OSD are doing this and zapping and readding it does
>> not solve the issue. Removing them completely from the cluster solve that issue, but I can't reuse their ID's. If I add another one with
>> the same ID it starts doing the same "funky" crashes. For now the cluster remains "stable" without the OSD's.
>>
>>
>>
>>
>> On Wed, Nov 23, 2016 at 4:00 PM, Nick Fisk <nick@xxxxxxxxxx> wrote:
>> > I take it you have size =2 or min_size=1 or something like that for the cache pool? 1 OSD shouldn’t prevent PG's from recovering.
>> >
>> > Your best bet would be to see if the PG that is causing the assert can be removed and let the OSD start up. If you are lucky, the PG
>> causing the problems might not be one which also has unfound objects, otherwise you are likely have to get heavily involved in
>> recovering objects with the object store tool.
>> >
>> >> -----Original Message-----
>> >> From: Daznis [mailto:daznis@xxxxxxxxx]
>> >> Sent: 23 November 2016 13:56
>> >> To: Nick Fisk <nick@xxxxxxxxxx>
>> >> Cc: ceph-users <ceph-users@xxxxxxxxxxxxxx>
>> >> Subject: Re:  Ceph strange issue after adding a cache OSD.
>> >>
>> >> No, it's still missing some PGs and objects and can't recover as it's
>> >> blocked by that OSD. I can boot the OSD up by removing all the PG
>> >> related files from current directory, but that doesn't solve the missing objects problem. Not really sure if I can move the object
>> back to their place manually, but I will try it.
>> >>
>> >> On Wed, Nov 23, 2016 at 3:08 PM, Nick Fisk <nick@xxxxxxxxxx> wrote:
>> >> > Sorry, I'm afraid I'm out of ideas about that one, that error
>> >> > doesn't mean very much to me. The code suggests the OSD is trying
>> >> > to
>> >> get an attr from the disk/filesystem, but for some reason it doesn't
>> >> like that. You could maybe whack the debug logging for OSD and
>> >> filestore up to max and try and see what PG/file is accessed just before the crash, but I'm not sure what the fix would be, even if
>> you manage to locate the dodgy PG.
>> >> >
>> >> > Does the cluster have all PG's recovered now? Unless anyone else
>> >> > can comment, you might be best removing/wiping and then re-
>> >> adding the OSD.
>> >> >
>> >> >> -----Original Message-----
>> >> >> From: Daznis [mailto:daznis@xxxxxxxxx]
>> >> >> Sent: 23 November 2016 12:55
>> >> >> To: Nick Fisk <nick@xxxxxxxxxx>
>> >> >> Cc: ceph-users <ceph-users@xxxxxxxxxxxxxx>
>> >> >> Subject: Re:  Ceph strange issue after adding a cache OSD.
>> >> >>
>> >> >> Thank you. That helped quite a lot. Now I'm just stuck with one OSD crashing with:
>> >> >>
>> >> >> osd/PG.cc: In function 'static int
>> >> >> PG::peek_map_epoch(ObjectStore*, spg_t, epoch_t*,
>> >> >> ceph::bufferlist*)' thread 7f36bbdd6880 time
>> >> >> 2016-11-23 13:42:43.27
>> >> >> 8539
>> >> >> osd/PG.cc: 2911: FAILED assert(r > 0)
>> >> >>
>> >> >>  ceph version 0.94.9 (fe6d859066244b97b24f09d46552afc2071e6f90)
>> >> >>  1: (ceph::__ceph_assert_fail(char const*, char const*, int, char
>> >> >> const*)+0x85) [0xbde2c5]
>> >> >>  2: (PG::peek_map_epoch(ObjectStore*, spg_t, unsigned int*,
>> >> >> ceph::buffer::list*)+0x8ba) [0x7cf4da]
>> >> >>  3: (OSD::load_pgs()+0x9ef) [0x6bd31f]
>> >> >>  4: (OSD::init()+0x181a) [0x6c0e8a]
>> >> >>  5: (main()+0x29dd) [0x6484bd]
>> >> >>  6: (__libc_start_main()+0xf5) [0x7f36b916bb15]
>> >> >>  7: /usr/bin/ceph-osd() [0x661ea9]
>> >> >>
>> >> >> On Wed, Nov 23, 2016 at 12:31 PM, Nick Fisk <nick@xxxxxxxxxx> wrote:
>> >> >> >> -----Original Message-----
>> >> >> >> From: Daznis [mailto:daznis@xxxxxxxxx]
>> >> >> >> Sent: 23 November 2016 10:17
>> >> >> >> To: nick@xxxxxxxxxx
>> >> >> >> Cc: ceph-users <ceph-users@xxxxxxxxxxxxxx>
>> >> >> >> Subject: Re:  Ceph strange issue after adding a cache OSD.
>> >> >> >>
>> >> >> >> Hi,
>> >> >> >>
>> >> >> >>
>> >> >> >> Looks like one of my colleagues increased the PG number before
>> >> >> >> it finished. I was flushing the whole cache tier and it's
>> >> >> >> currently stuck on ~80 GB of data, because of the OSD crashes.
>> >> >> >> I will look into the hitset counts and check what can be done.
>> >> >> >> Will provide an
>> >> >> update if I find anything or fix the issue.
>> >> >> >
>> >> >> > So I'm guessing when the PG split, the stats/hit_sets are not
>> >> >> > how the OSD is expecting them to be and causes the crash. I
>> >> >> > would
>> >> >> expect this has been caused by the PG splitting rather than
>> >> >> introducing extra OSD's. If you manage to get things stable by
>> >> >> bumping up the hitset count, then you probably want to try and do
>> >> >> a scrub to try and clean up the stats, which may then stop this
>> >> happening when the hitset comes round to being trimmed again.
>> >> >> >
>> >> >> >>
>> >> >> >>
>> >> >> >> On Wed, Nov 23, 2016 at 12:04 PM, Nick Fisk <nick@xxxxxxxxxx> wrote:
>> >> >> >> > Hi Daznis,
>> >> >> >> >
>> >> >> >> > I'm not sure how much help I can be, but I will try my best.
>> >> >> >> >
>> >> >> >> > I think the post-split stats error is probably benign,
>> >> >> >> > although I think this suggests you also increased the number
>> >> >> >> > of PG's in your cache pool? If so did you do this before or
>> >> >> >> > after you added the
>> >> >> >> extra OSD's?  This may have been the cause.
>> >> >> >> >
>> >> >> >> > On to the actual assert, this looks like it's part of the
>> >> >> >> > code which trims the tiering hit set's. I don't understand
>> >> >> >> > why its crashing out, but it must be related to an invalid or
>> >> >> >> > missing hitset I would
>> >> >> >> imagine.
>> >> >> >> >
>> >> >> >> > https://github.com/ceph/ceph/blob/v0.94.9/src/osd/ReplicatedP
>> >> >> >> > G.c
>> >> >> >> > c#L
>> >> >> >> > 104
>> >> >> >> > 85
>> >> >> >> >
>> >> >> >> > The only thing I could think of from looking at in the code
>> >> >> >> > is that the function loops through all hitsets that are above
>> >> >> >> > the max number (hit_set_count). I wonder if setting this
>> >> >> >> > number higher would
>> >> >> >> mean it won't try and trim any hitsets and let things recover?
>> >> >> >> >
>> >> >> >> > DISCLAIMER
>> >> >> >> > This is a hunch, it might not work or could possibly even
>> >> >> >> > make things worse. Otherwise wait for someone who has a better idea to comment.
>> >> >> >> >
>> >> >> >> > Nick
>> >> >> >> >
>> >> >> >> >
>> >> >> >> >
>> >> >> >> >> -----Original Message-----
>> >> >> >> >> From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx]
>> >> >> >> >> On Behalf Of Daznis
>> >> >> >> >> Sent: 23 November 2016 05:57
>> >> >> >> >> To: ceph-users <ceph-users@xxxxxxxxxxxxxx>
>> >> >> >> >> Subject:  Ceph strange issue after adding a cache OSD.
>> >> >> >> >>
>> >> >> >> >> Hello,
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >> The story goes like this.
>> >> >> >> >> I have added another 3 drives to the caching layer. OSDs
>> >> >> >> >> were added to crush map one by one after each successful rebalance.
>> >> >> >> >> When
>> >> >> >> > I
>> >> >> >> >> added the last OSD and went away for about an hour I noticed
>> >> >> >> >> that it's still not finished rebalancing. Further
>> >> >> >> >> investigation
>> >> >> >> > showed me
>> >> >> >> >> that it one of the older cache SSD was restarting like crazy
>> >> >> >> >> before full boot. So I shut it down and waited for a
>> >> >> >> >> rebalance
>> >> >> >> > without that
>> >> >> >> >> OSD. Less than an hour later I had another 2 OSD restarting
>> >> >> >> >> like crazy. I tried running scrubs on the PG's logs asked me
>> >> >> >> >> to, but
>> >> >> >> > that did
>> >> >> >> >> not help. I'm currently stuck with " 8 scrub errors" and a complete dead cluster.
>> >> >> >> >>
>> >> >> >> >> log_channel(cluster) log [WRN] : pg 15.8d has invalid
>> >> >> >> >> (post-split) stats; must scrub before tier agent can
>> >> >> >> >> activate
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >> I need help with OSD from crashing. Crash log:
>> >> >> >> >>      0> 2016-11-23 06:41:43.365602 7f935b4eb700 -1
>> >> >> >> >> osd/ReplicatedPG.cc: In function 'void
>> >> >> >> >> ReplicatedPG::hit_set_trim(ReplicatedPG::RepGather*, unsigned int)'
>> >> >> >> >> thread 7f935b4eb700 time 2016-11-23 06:41:43.363067
>> >> >> >> >> osd/ReplicatedPG.cc: 10521: FAILED assert(obc)
>> >> >> >> >>
>> >> >> >> >>  ceph version 0.94.9
>> >> >> >> >> (fe6d859066244b97b24f09d46552afc2071e6f90)
>> >> >> >> >>  1: (ceph::__ceph_assert_fail(char const*, char const*, int,
>> >> >> >> >> char
>> >> >> >> >> const*)+0x85) [0xbde2c5]
>> >> >> >> >>  2: (ReplicatedPG::hit_set_trim(ReplicatedPG::RepGather*,
>> >> >> >> >> unsigned
>> >> >> >> >> int)+0x75f) [0x87e89f]
>> >> >> >> >>  3: (ReplicatedPG::hit_set_persist()+0xedb) [0x87f8bb]
>> >> >> >> >>  4:
>> >> >> >> >> (ReplicatedPG::do_op(std::tr1::shared_ptr<OpRequest>&)+0xe3a
>> >> >> >> >> )
>> >> >> >> >> [0x8a11aa]
>> >> >> >> >>  5:
>> >> >> >> >> (ReplicatedPG::do_request(std::tr1::shared_ptr<OpRequest>&,
>> >> >> >> >> ThreadPool::TPHandle&)+0x68a) [0x83c37a]
>> >> >> >> >>  6: (OSD::dequeue_op(boost::intrusive_ptr<PG>,
>> >> >> >> >> std::tr1::shared_ptr<OpRequest>,
>> >> >> >> >> ThreadPool::TPHandle&)+0x405) [0x69af05]
>> >> >> >> >>  7: (OSD::ShardedOpWQ::_process(unsigned int,
>> >> >> >> >> ceph::heartbeat_handle_d*)+0x333) [0x69b473]
>> >> >> >> >>  8: (ShardedThreadPool::shardedthreadpool_worker(unsigned
>> >> >> >> >> int)+0x86f) [0xbcd9cf]
>> >> >> >> >>  9: (ShardedThreadPool::WorkThreadSharded::entry()+0x10)
>> >> >> >> >> [0xbcfb00]
>> >> >> >> >>  10: (()+0x7dc5) [0x7f93b9df4dc5]
>> >> >> >> >>  11: (clone()+0x6d) [0x7f93b88d5ced]
>> >> >> >> >>  NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this.
>> >> >> >> >>
>> >> >> >> >>
>> >> >> >> >> I have tried looking with  full debug enabled, but those
>> >> >> >> >> logs didn't help me much. I have tried to evict the cache
>> >> >> >> >> layer, but some objects are stuck and can't be removed. Any
>> >> >> >> >> suggestions would be
>> >> >> >> greatly appreciated.
>> >> >> >> >> _______________________________________________
>> >> >> >> >> ceph-users mailing list
>> >> >> >> >> ceph-users@xxxxxxxxxxxxxx
>> >> >> >> >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>> >> >> >> >
>> >> >> >
>> >> >
>> >
>> _______________________________________________
>> ceph-users mailing list
>> ceph-users@xxxxxxxxxxxxxx
>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>
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