I strongly suggest disabling delayed_commits on general principles (what's
written should stay written). Are you able to compact the database(s) that give
this error?
B.
On 7 Aug 2012, at 18:42, stephen bartell wrote:
> delayed_commits = true
>
> Stephen Bartell
>
> On Aug 7, 2012, at 10:39 AM, Robert Newson wrote:
>
>> Are you running with delayed_commits=true or false?
>>
>> B.
>>
>> On 7 Aug 2012, at 18:27, stephen bartell wrote:
>>
>>>
>>>> Hi Stephen,
>>>>
>>>> Can you tell us anymore about the context, or did you start seeing these
>>>> in the logs?
>>>
>>> Sure, here's some context. This couch is part of a demo server. It
>>> travels a lot and is cycled a lot. There is one physical server, it
>>> consists of nginx (serving web apps and reverse proxying for couch),
>>> couchdb for persistence, and numerous programs which read and write to
>>> couch. Traffic on couch can get very heavy.
>>>
>>> I didn't first see this in the logs. Some of the web apps would grind to a
>>> halt, nginx would return 404, and then eventually couch would restart.
>>> This would happen every couple of minutes.
>>>
>>>> By chance do you have a scenario that reproduces this? Was this db
>>>> compacted or replicated from elsewhere?
>>>
>>> I wish I had a pliable scenario other than sending the server through taxi
>>> cabs, airlines, and pulling the power cord several times a day. We haven't
>>> seen this on any of our production servers.
>>> This server was not subject to any replication. Most databases on it are
>>> compacted often.
>>>
>>> Last night we were able to drill down to one particular program which was
>>> triggering the crash. One by one, we backed up, deleted, and rebuilt the
>>> databases that program touched. There was one database which seemed to be
>>> the culprit, lets call it History. History is a dumping ground for stale
>>> docs from another db. History is almost always written to, and rarely read
>>> from. We don't compact History since all docs in it are one revision
>>> deep. We never replicate to or from it. The only reason we deem History
>>> the culprit is because after rebuilding it, there hasn't been a crash for
>>> over 12 hours.
>>>
>>> I have an additional question. Is it possible to turn couch logging off
>>> entirely, or would redirecting to dev/null suffice? When couch would
>>> crash, hundreds of MB of crap would get dumped to the log. (
>>> {{badmatch,{ok,<<32,50,48,48,10 … 'hundreds of MB of crap' … ,0,3,232>>}}).
>>> Right when this dump occurred, the cpu spiked and the server began its
>>> downward descent.
>>>
>>> Best
>>>
>>>>
>>>> Thanks,
>>>>
>>>> Bob
>>>> On Aug 7, 2012, at 2:06 AM, stephen bartell <[email protected]> wrote:
>>>>
>>>>> Hi all, could some one help shed some light on this crash I'm having.
>>>>> I'm on v1.2, ubuntu 11.04.
>>>>>
>>>>> [Mon, 06 Aug 2012 18:29:16 GMT] [error] [<0.492.0>] ** Generic server
>>>>> <0.492.0> terminating
>>>>> ** Last message in was {pread_iolist,88385709}
>>>>> ** When Server state ==
>>>>> {file,{file_descriptor,prim_file,{#Port<0.2899>,79}},
>>>>> 93302896}
>>>>> ** Reason for termination ==
>>>>> ** {{badmatch,{ok,<<32,50,48,48,10 … huge dump … ,0,3,232>>}},
>>>>> [{couch_file,read_raw_iolist_int,3},
>>>>> {couch_file,maybe_read_more_iolist,4},
>>>>> {couch_file,handle_call,3},
>>>>> {gen_server,handle_msg,5},
>>>>> {proc_lib,init_p_do_apply,3}]}
>>>>>
>>>>> I'm not too familiar with erlang, but what I gathered from the src was
>>>>> `pread_iolist` function is used when reading anything from the disk. So
>>>>> I think this might be a corrupt db problem.
>>>>>
>>>>> Thanks,
>>>>> Stephen Bartell
>>>>
>>>
>>
>
