[Dovecot] dsync mirror duplicates problem
Im trying to sync 2 mailserver with dsync mirror functionality.
Problem occurs when mails arrive in the same folder on both sides then dsync sometimes runs into problems and duplicates that entrys on both side(2mails then with same content). After running again the same happens again(now 4 mails with same content on every side). And then duplicates this mails on both sides on every run :( Anyone with same problem or is something that could cause this? I tried dsync with and without -f option but no change.
Im running dovecot 2.0.1 together with dovecot sieve (latest hg version).
thanks, Waldemar
On Sat, 28 Aug 2010 17:58:38 +0200, "Waldemar W." dovecot@serpent.aes256.de wrote:
Im trying to sync 2 mailserver with dsync mirror functionality.
Problem occurs when mails arrive in the same folder on both sides then dsync sometimes runs into problems and duplicates that entrys on both side(2mails then with same content). After running again the same happens again(now 4 mails with same content on every side). And then duplicates this mails on both sides on every run :( Anyone with same problem or is something that could cause this? I tried dsync with and without -f option but no change.
Im running dovecot 2.0.1 together with dovecot sieve (latest hg version).
thanks, Waldemar
After seeing that mirror seems not to work fine i tried a "backup" only solution with dsync. But after 1 day there are other problems on almost all accounts i tried to sync like: "Warning: Destination mailbox INBOX has been modified, need to recreate it before we can continue syncing Error: Can't delete mailbox INBOX: INBOX can't be deleted." This appears on 4 of the 8 Accounts i tried to sync. On other one there appears "Error: msg-copy returned invalid uid: 1269868747 != 1" and on one a msg like "Error: Unexpected finish reply: +".
For my initial sync i used complete empty maildirs on the destination server and from that on only working with the "backup" option of dsync. Any idea what could cause such big problems with dsync?
thanks, Waldemar
On Sat, 2010-08-28 at 17:58 +0200, Waldemar W. wrote:
Problem occurs when mails arrive in the same folder on both sides then dsync sometimes runs into problems and duplicates that entrys on both side(2mails then with same content). After running again the same happens again(now 4 mails with same content on every side). And then duplicates this mails on both sides on every run :( Anyone with same problem or is something that could cause this? I tried dsync with and without -f option but no change.
Oh, right.. The old conflict resolution method worked only with Maildir. The new conflict resolution method works with everything except Maildir.
The problem is that the new method works by first copying the message to give it a new UID but preserve its GUID, and then expunging the old one. But with Maildir the message filename is the GUID, so it's not possible to have two messages in the same mailbox with the same GUID. So Dovecot gives a new filename/GUID to the copied message, which dsync next time thinks is conflicting and tries to resolve it, and then this continues forever..
Hmm.. I guess one solution to this would be to allow overriding the filename as GUID in dovecot-uidlist.. Or I can't really even think of any other solution. Hopefully won't be too horribly difficult to implement it.
On Wed, 2010-09-15 at 19:30 +0100, Timo Sirainen wrote:
Hmm.. I guess one solution to this would be to allow overriding the filename as GUID in dovecot-uidlist.. Or I can't really even think of any other solution. Hopefully won't be too horribly difficult to implement it.
Implemented: http://hg.dovecot.org/dovecot-2.0/rev/b93405cdd4e9
participants (2)
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Timo Sirainen
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Waldemar W.