Sure,
ceph-post-file: ebc211d2-5ae1-40ee-b40a-7668a21232e6
Contains the ceph logs and crashed OSD logs with default debug level.
The flapping problem starts @2016-09-09 20:57:14.230840 and the OSDs
crash (with suicide and corrupted leveldb logs) @2016-09-10 between
02:04 - 02:40. You will notice tha when we tried to start them some
hours later, the OSDs kept crashing but with different asserts.
On 16 September 2016 at 13:34, Haomai Wang <haomai@xxxxxxxx> wrote:
> On Fri, Sep 16, 2016 at 5:11 PM, Kostis Fardelas <dante1234@xxxxxxxxx> wrote:
>> (sent this email to ceph-users too, but there was no feedback due to
>> to its complex issues I guess, so I am sending this in ceph-devel too.
>> Thanks)
>>
>> Hello cephers,
>> last week we survived a 3-day outage on our ceph cluster (Hammer
>> 0.94.7, 162 OSDs, 27 "fat" nodes, 1000s of clients) due to 6 out of
>> 162 OSDs crash in the SAME node. The outage was caused in the
>> following timeline:
>> time 0: OSDs living in the same node (rd0-19) start heavily flapping
>> (in the logs: failed, wrongly marked me down, RESETSESSION etc). Some
>> more OSDs on other nodes are also flapping but the OSDs of this single
>> node seem to have played the major part in this problem
>>
>> time +6h: rd0-19 OSDs assert. Two of them suicide on OSD::osd_op_tp
>> thread timeout and the other ones assert with EPERM and corrupted
>> leveldb related errors. Something like this:
>>
>> 2016-09-10 02:40:47.155718 7f699b724700 0 filestore(/rados/rd0-19-01)
>> error (1) Operation not permitted not handled on operation 0x46db2d00
>> (1731767079.0.0, or op 0, counting from 0)
>> 2016-09-10 02:40:47.155731 7f699b724700 0 filestore(/rados/rd0-19-01)
>> unexpected error code
>> 2016-09-10 02:40:47.155732 7f699b724700 0 filestore(/rados/rd0-19-01)
>> transaction dump:
>> {
>> "ops": [
>> {
>> "op_num": 0,
>> "op_name": "omap_setkeys",
>> "collection": "3.b30_head",
>> "oid": "3\/b30\/\/head",
>> "attr_lens": {
>> "_epoch": 4,
>> "_info": 734
>> }
>> }
>> ]
>> }
>>
>>
>> 2016-09-10 02:40:47.155778 7f699671a700 -1 os/FileStore.cc: In
>> function 'unsigned int
>> FileStore::_do_transaction(ObjectStore::Transaction&, uint64_t, int,
>> ThreadPool::TPH
>> andle*)' thread 7f699671a700 time 2016-09-10 02:40:47.153544
>> os/FileStore.cc: 2761: FAILED assert(0 == "unexpected error")
>>
>> This leaves the cluster in a state like below:
>> 2016-09-10 03:04:31.927635 mon.0 62.217.119.14:6789/0 948003 : cluster
>> [INF] osdmap e281474: 162 osds: 156 up, 156 in
>> 2016-09-10 03:04:32.145074 mon.0 62.217.119.14:6789/0 948004 : cluster
>> [INF] pgmap v105867219: 28672 pgs: 1
>> active+recovering+undersized+degraded, 26684 active+clean, 1889
>> active+undersized+degraded, 98 down+peering; 95983 GB data, 179 TB
>> used, 101379 GB / 278 TB avail; 12106 B/s rd, 11 op/s;
>> 2408539/69641962 objects degraded (3.458%); 1/34820981 unfound
>> (0.000%)
>>
>> From this time we have almost no IO propably due to 98 down+peering
>> PGs, 1 unfound object and 1000s of librados clients stuck.
>> As of now, we have not managed to pinpoint what caused the crashes (no
>> disk errors, no network errors, no general hardware errors, nothing in
>> dmesg) but things are still under investigation. Finally we managed to
>> bring up enough crashed OSDs for IO to continue (using gdb, leveldb
>> repairs, ceph-objectstore-tool), but our main questions exists:
>>
>> A. the 6 OSDs were on the same node. What is so special about
>> suiciding + EPERMs that leave the cluster with down+peering and zero
>> IO? Is this a normal behaviour after a crash like this? Notice that
>> the cluster has marked the crashed OSDs down+out, so it seems that the
>> cluster somehow "fenced" these OSDs but in a manner that leaves the
>> cluster unusable. Our crushmap is the default one with the host as a
>> failure domain
>> B. would replication=3 help? Would we need replication=3 and min=2 to
>> avoid such a problem in the future? Right now we are on size=2 &
>> min_size=1
>> C. would an increase in suicide timeouts help for future incidents like this?
>> D. are there any known related bugs on 0.94.7? Haven't found anything so far...
>
> Could you please provide with ceph.log and the down osd logs at that
> time? I don't have clue in your description so far.
>
>>
>> Regards,
>> Kostis
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