seen db

[Rudy Gevaert]

Bron Gondwana wrote:
> On Tue, 10 Jun 2008 15:29:01 +0200, "Rudy Gevaert" <Rudy.Gevaert at UGent.be> said:
>> Bron Gondwana wrote:
>>
>>> Are you running a 64 bit kernel?
>> Yes, but the system is 32bit (I run 64bit kernel  + 32 emulation support)
> 
> Interesting, so do we (on etch as well)
> 
>>> (just wondering - we have hit pretty much the same issue - and were
>>> wondering about dodgy kernel issues being a proble - it's only one
>>> machine that seems to have corrupted seen files, only on replicas)
>>
>>> We've been running 2.3.12 for about a week, and it's only last night
>>> that we had anything funny show up at all.
>>>
>>> Interestingly, it's probably the first time cyr_expire ran on 2.3.12
>>> just before that - and also the first time our check-replication
>>> script was running, which loads a lot of seen files on BOTH ends.
>> Here cyr_expire has been running on 2.3.12 for a couple of weeks.  But 
>> here the first time too with the 64bit kernel.
> 
> There you go.  We've had the 64bit kernel approximately forever, but only
> just upgraded from 2.6.20 series to 2.6.25.
> 
>> I can try with a 32bit kernel tomorrow.

Unfortunate with the 32bit kernel 2.6.24-2 it sync_server still segfaults.


>> In attachment a strace to show where it segfaults
> 
> Almost certainly boring, since it's file corruption.  The file itself would
> be significantly more interesting.  My guess - you'll be finding little blocks
> of (small n)*4 bytes which happen to be NULL.  It's when they intersect with
> the pointers table that things get interesting.



> Oh - can you tell me.  Did the file checkpoint sometime not too long before it
> got corrupted?

The cases I saw it did.

> I've got a small set of theories, but I'm reading the skiplist source code
> (again!) to see if they make sense...
> 
> Bron.

I'm also wondering if what would happen if I brought up a master. 
Surely the imap processes would also segfault.  Right?

Here I can delete the mailbox on the replica and sync again.  As a 
reconstruct doesn't help.


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Rudy Gevaert          Rudy.Gevaert at UGent.be          tel:+32 9 264 4734
Directie ICT, afd. Infrastructuur ICT Department, Infrastructure office
Groep Systemen                    Systems group
Universiteit Gent                 Ghent University
Krijgslaan 281, gebouw S9, 9000 Gent, Belgie               www.UGent.be
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