[Dovecot] Sudden, large numbers of "Timeout while waiting for lock for transaction log ..."

[Jack Stewart]

Hi,

Up until yesterday, our environment which consists an NFS maildir file 
store with multiple front end servers, was working fine. We've verified 
that the server clocks and machines clocks are in sync.


Starting yesterday afternoon, We are getting ~850 log entries of the 
form 'Timeout while waiting for lock for transaction log files' or 'Our 
dotlock file was modified, assuming it wasn't overridden (kept it 180 sec)

Based on packet capture, just one of these index files shows 28553 
GETATTRs queries in in a one minute.


At this happened at exactly the same time on all of our servers, it is 
pretty clear that the back-end system (or network) is a major factor 
although nobody will confess that they made any changes.

It would be helpful, and very appreciated, to get more information about 
what this might be so that we can nudge the correct people to undo 
whatever it is that they didn't do.

We are running currently dovecot 1.1.3



an  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Timeout while 
waiting for lock for transaction log file 
/var/spool/dovecot/indexes/z/zabala/.INBOX/dovecot.index.log
Jan  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Our dotlock file 
/var/spool/maildir/z/zabala/dovecot-uidlist.lock was deleted (kept it 
180 secs)
Jan  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Timeout while 
waiting for lock for transaction log file 
/var/spool/dovecot/indexes/z/zabala/.INBOX/dovecot.index.log
Jan  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Our dotlock file 
/var/spool/maildir/z/zabala/dovecot-uidlist.lock was modified 
(1231233482 vs 1231233662), assuming it wasn't overridden (kept it 180 secs)
Jan  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Timeout while 
waiting for lock for transaction log file 
/var/spool/dovecot/indexes/z/zabala/.INBOX/dovecot.index.log
Jan  6 01:21:02 earth-griffen dovecot: IMAP(zabala): Our dotlock file 
/var/spool/maildir/z/zabala/dovecot-uidlist.lock was modified 
(1231233482 vs 1231233662), assuming it wasn't overridden (kept it 180 secs)
Jan  6 01:21:04 fire-griffen dovecot: IMAP(sukwon): Timeout while 
waiting for lock for transaction log file 
/var/spool/dovecot/indexes/s/sukwon/.Trash/dovecot.index.log





-- 
Jack Stewart
Academic Computing Services, IMSS,
California Institute of Technology
jstewart at caltech.edu
626-395-4690 office