On Sun, Oct 11, 2015 at 7:36 PM, Milosz Tanski <mil...@adfin.com> wrote: > On Sun, Oct 11, 2015 at 6:44 PM, Milosz Tanski <mil...@adfin.com> wrote: >> On Sun, Oct 11, 2015 at 6:01 PM, Milosz Tanski <mil...@adfin.com> wrote: >>> On Sun, Oct 11, 2015 at 5:33 PM, Milosz Tanski <mil...@adfin.com> wrote: >>>> On Sun, Oct 11, 2015 at 5:24 PM, Milosz Tanski <mil...@adfin.com> wrote: >>>>> On Sun, Oct 11, 2015 at 1:16 PM, Gregory Farnum <gfar...@redhat.com> >>>>> wrote: >>>>>> On Sun, Oct 11, 2015 at 10:09 AM, Milosz Tanski <mil...@adfin.com> wrote: >>>>>>> About an hour ago my MDSs (primary and follower) started ping-pong >>>>>>> crashing with this message. I've spent about 30 minutes looking into >>>>>>> it but nothing yet. >>>>>>> >>>>>>> This is from a 0.94.3 MDS >>>>>>> >>>>>> >>>>>>> 0> 2015-10-11 17:01:23.596008 7fd4f52ad700 -1 mds/SessionMap.cc: >>>>>>> In function 'virtual void C_IO_SM_Save::finish(int)' thread >>>>>>> 7fd4f52ad700 time 2015-10-11 17:01:23.594089 >>>>>>> mds/SessionMap.cc: 120: FAILED assert(r == 0) >>>>>> >>>>>> These "r == 0" asserts pretty much always mean that the MDS did did a >>>>>> read or write to RADOS (the OSDs) and got an error of some kind back. >>>>>> (Or in the case of the OSDs, access to the local filesystem returned >>>>>> an error, etc.) I don't think these writes include any safety checks >>>>>> which would let the MDS break it which means that probably the OSD is >>>>>> actually returning an error — odd, but not impossible. >>>>>> >>>>>> Notice that the assert happened in thread 7fd4f52ad700, and look for >>>>>> the stuff in that thread. You should be able to find an OSD op reply >>>>>> (on the SessionMap object) coming in and reporting an error code. >>>>>> -Greg >>>>> >>>>> I only two error ops in that whole MDS session. Neither one happened >>>>> on the same thread (7f5ab6000700 in this file). But it looks like the >>>>> only session map is the -90 "Message too long" one. >>>>> >>>>> mtanski@tiny:~$ cat single_crash.log | grep 'osd_op_reply' | grep -v >>>>> 'ondisk = 0' >>>>> -3946> 2015-10-11 20:51:11.013965 7f5ab20f2700 1 -- >>>>> 10.0.5.31:6802/27121 <== osd.25 10.0.5.57:6804/32341 6163 ==== >>>>> osd_op_reply(46349 mds0_sessionmap [writefull 0~95168363] v0'0 uv0 >>>>> ondisk = -90 ((90) Message too long)) v6 ==== 182+0+0 (2955408122 0 0) >>>>> 0x3a55d340 con 0x3d5a3c0 >>>>> -705> 2015-10-11 20:51:11.374132 7f5ab22f4700 1 -- >>>>> 10.0.5.31:6802/27121 <== osd.28 10.0.5.50:6801/1787 5297 ==== >>>>> osd_op_reply(48004 300.0000e274 [delete] v0'0 uv1349638 ondisk = -2 >>>>> ((2) No such file or directory)) v6 ==== 179+0+0 (1182549251 0 0) >>>>> 0x66c5c80 con 0x3d5a7e0 >>>>> >>>>> Any idea what this could be Greg? >>>> >>>> To follow this up I found this ticket from 9 months ago: >>>> http://tracker.ceph.com/issues/10449 In there Yan says: >>>> >>>> "it's a kernel bug. hang request prevents mds from trimming >>>> completed_requests in sessionmap. there is nothing to do with mds. >>>> (maybe we should add some code to MDS to show warning when this bug >>>> happens)" >>>> >>>> When I was debugging this I saw an OSD (not cephfs client) operation >>>> stuck for a long time along with the MDS error: >>>> >>>> HEALTH_WARN 1 requests are blocked > 32 sec; 1 osds have slow >>>> requests; mds cluster is degraded; mds0: Behind on trimming (709/30) >>>> 1 ops are blocked > 16777.2 sec >>>> 1 ops are blocked > 16777.2 sec on osd.28 >>>> >>>> I did eventually bounce the OSD in question and it hasn't become stuck >>>> since, but the MDS is still eating it every time with the "Message too >>>> long" error on the session map. >>>> >>>> I'm not quite sure where to go from here. >>> >>> First time I had a chance to use the new recover tools. I was able to >>> reply the journal, reset it and then reset the sessionmap. MDS >>> returned back to life and so far everything looks good. Yay. >>> >>> Triggering this a bug/issue is a pretty interesting set of steps. >> >> Spoke too soon, a missing dir is now causing MDS to restart it self. >> >> -6> 2015-10-11 22:40:47.300169 7f580c7b9700 5 -- op tracker -- >> seq: 4, time: 2015-10-11 22:40:47.300168, event: finishing request, >> op: client_request(client.3597476:21480382 rmdir #100015e0be2/58 >> 2015-10-11 21:34:49.224905 RETRY=36) >> -5> 2015-10-11 22:40:47.300208 7f580c7b9700 5 -- op tracker -- >> seq: 4, time: 2015-10-11 22:40:47.300208, event: cleaned up request, >> op: client_request(client.3597476:21480382 rmdir #100015e0be2/58 >> 2015-10-11 21:34:49.224905 RETRY=36) >> -4> 2015-10-11 22:40:47.300231 7f580c7b9700 5 -- op tracker -- >> seq: 4, time: 2015-10-11 22:40:47.300231, event: done, op: >> client_request(client.3597476:21480382 rmdir #100015e0be2/58 >> 2015-10-11 21:34:49.224905 RETRY=36) >> -3> 2015-10-11 22:40:47.300284 7f580e0bd700 0 >> mds.0.cache.dir(100048df076) _fetched missing object for [dir >> 100048df076 /petabucket/beta/6d/f6/ [2,head] auth v=0 cv=0/0 ap=1+0+0 >> state=1073741952 f() n() hs=0+0,ss=0+0 | waiter=1 authpin=1 0x6debcf8] >> -2> 2015-10-11 22:40:47.300313 7f580e0bd700 -1 >> log_channel(cluster) log [ERR] : dir 100048df076 object missing on >> disk; some files may be lost >> -1> 2015-10-11 22:40:47.300549 7f580c7b9700 5 -- op tracker -- >> seq: 6, time: 2015-10-11 22:40:47.300549, event: acquired locks, op: >> client_request(client.3710941:1805 mkdir >> #100048df076/1dd4c66b916cf55f19beafc0574ac2dd923bc7efcc5b7757198f323e04d0.dl >> 2015-10-11 22:36:32.489705 RETRY=33) >> 0> 2015-10-11 22:40:47.303770 7f580c7b9700 -1 mds/CDir.cc: In >> function 'fnode_t* CDir::project_fnode()' thread 7f580c7b9700 time >> 2015-10-11 22:40:47.300581 >> mds/CDir.cc: 1267: FAILED assert(get_version() != 0) >> >> ceph version 0.94.3 (95cefea9fd9ab740263bf8bb4796fd864d9afe2b) >> 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char >> const*)+0x8b) [0x94cc1b] >> 2: (CDir::project_fnode()+0x2da) [0x75da1a] > > Worked around this as well. Stopped the client that was trying to > access this dir (or delete it, not sure) and move it somewhere else > (because I can't delete it). > > A series of steps that happened today (not sure if all are related) in > case the postmortem is interesting to anybody following at home. > > 1. One (of 5) monitors somehow gets OOM killed after eating up 10gigs of ram. > 2. An OSD blocks on an IO request > 3. This is when the MSD starts growing it's SessionMap to a place > where eventually it gets to big. This is related to bug: > http://tracker.ceph.com/issues/10449 (not the client bug, but the too > large Session) > 4. MDS suicides and then two MDS machines start ping ponging in > recovery but always fail to save SessionMap. > 5. I stop the MDS, recover the journal and reset the session map.
Exactly what did you do in this step? I have a suspicion you didn't recover and flush out the journal all the way, and that's what caused your directory to go bad. -Greg > 6. MDS come back to life after that. > 7. Ceph loses one directory and as soon as the client tries to access > it the MDS also suicides. Standing bug: > http://tracker.ceph.com/issues/9880 > 8. Lame workaround (moving / renaming bad dir) so client doesn't access it. > > -- > Milosz Tanski > CTO > 16 East 34th Street, 15th floor > New York, NY 10016 > > p: 646-253-9055 > e: mil...@adfin.com -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
