dovecot - May 2006 - Solution: NFS & Dovecot!

Hi folks!

It looks like Timo nailed down the NFS issues we've been seeing here in
last night's CVS build.

Anyone running Dovecot in a high-usage environment should check this out.

Here are some relevant ChangeLog updates that seem to address the problem:

2006-05-02 11:11  Timo Sirainen <timo.sirainen at movial.fi>

	* src/lib-storage/index/maildir/: maildir-save.c,
	  maildir-storage.h, maildir-sync.c, maildir-uidlist.c,
	  maildir-uidlist.h: Adding mail to index while saving it had a
	  race condition. Fixing it required a bit larger changes. Switched
	  uidlist/index locking order so that uidlist is now locked first.

2006-05-02 11:04  Timo Sirainen <timo.sirainen at movial.fi>

	* src/lib-index/: mail-index-private.h, mail-index-sync-update.c,
	  mail-index.c: mmap_disable: When syncing in-memory index from
	  transaction log, we didn't skip external transactions which were
	  already been in our in-memory mapping, causing "Append with UID
	  n, but next_uid = m" errors.

The build is available here:

http://dovecot.org/nightly/dovecot-20060503.tar.gz

Thus far, I've seen no complaints of corrupted indexes or core dumps. 
This is absolutely fantastic.

As always... hats off to Timo.  Great work!

Steve

On Wed, May 03, 2006 at 09:51:54AM -0400, Apps Lists
wrote:
> Hi folks!
> 
> It looks like Timo nailed down the NFS issues we've been seeing here in
> last night's CVS build.
I can confirm that the UID complains in logs have vanished.

I'm still seeing, very occasionally (on a very busy server)
the following inexplicable sequence:

May  4 15:02:19 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:02:23 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127
May  4 15:02:44 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:02:44 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127
May  4 15:12:19 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:12:19 mailstore dovecot: POP3(user2 at example.net): Corrupted index
cache file /var/mailstore/mail/user2 at example.net/dovecot.index.cache: invalid
field header size
May  4 15:12:19 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127
May  4 15:22:20 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:22:20 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127
May  4 15:22:44 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:22:45 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127
May  4 15:32:20 mailstore dovecot: pop3-login: Login: user=<user2 at
example.net>, method=PLAIN, rip=192.0.0.1, lip=192.0.0.2
May  4 15:32:20 mailstore dovecot: POP3(user2 at example.net): Corrupted index
cache file /var/mailstore/mail/user2 at example.net/dovecot.index.cache: invalid
field header size
May  4 15:32:20 mailstore dovecot: POP3(user2 at example.net): Disconnected:
Logged out top=0/0, retr=0/0, del=0/7, size=295127

no deliveries, no IMAP accesses.

(identities genericised)

Haven't tracked this down yet.  So far baffled and looking for patterns.
Seeing it about 10 times in every 100,000 logins (about an hour's worth).

Steve, are you using dotlocks or fcntl locks? (I see this with both,
talking to a netapp filer)

/JG