- dovecot - dovecot.org

Re: [Dovecot] Clustering (replication and proxying) plans for the future
by Bill Boebel 02 Nov '06

02 Nov '06

On Tue, October 24, 2006 2:31 pm, Timo Sirainen <tss(a)iki.fi> said: > The replication could work simply by sending the transaction logs' > contents to the replicatio process which passes it onto other servers, > which finally sync their local mailboxes based on that data. Since > Dovecot already is able to sync mailboxes based on the transaction log's > contents this should be pretty easy to implement. > > Of course the new mails' contents also have to be sent. This could be > prioritized lower than the transaction traffic, so that each server > always has very up-to-date view of the mailbox metadata, but not > necessarily the contents of all the mails. > > If the server finds itself in a situation that it doesn't have some > specific mail, it'll send a request to the replication process to fetch > it ASAP from another server. The reply will then take the highest > priority in the queue. Is your primary goal with this replication to add redundancy or to distribute load such as for shared mailboxes? I've thought about the redundancy side of this a lot, but not so much about load distribution. It sounds like you're going for load distribution, but... If the goal is redundancy, I'd suggest that mailbox state is less important than the mail data. Index files can be recreated from the data, and would not even be needed on the secondary server(s) unless the primary fails. So I'd put a higher priority on getting the mail content to the secondary servers. If the goal is to distribute load for shared mailboxes, then your prioritization makes sense. Also, if the goal is redundancy, this design can be simplified a lot by having one master and one or more slaves. All modify operations would go to the master, so that you do not need global locks. Different sets of users would belong to different namespaces, so that you can have multiple replication paths in your cluster. You'd also want an API for the replication process so that third-party applications that modify mailboxes can log those changes so that they are replicated. And in that case, the replication process could be made generic enough so that it can be used to replicate any set of files, with or without Dovecot. Bill

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[Dovecot] http://dovecot.org/tools/
by Gavin Henry 01 Nov '06

01 Nov '06

Dear all, Could this be added to http://dovecot.org/tools/ http://cpan.org/authors/id/G/GH/GHENRY/create_dovecot_shares-1.05 Thanks. -- Kind Regards, Gavin Henry. Managing Director. T +44 (0) 1224 279484 M +44 (0) 7930 323266 F +44 (0) 1224 824887 E ghenry(a)suretecsystems.com Open Source. Open Solutions(tm). http://www.suretecsystems.com/

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[Dovecot] CRASH: mail-cache-fields.c crash - new info, hacked 'solution'
by JB Zimmerman 01 Nov '06

01 Nov '06

I'm baaaaack. :-) I've managed to implement a suggestion from Hans Morten Kind from this list that seems to have stopped the crashing. However, my hack - commenting out a call to i_unreached() - makes me queasy because I have no idea of the ramifications of it (I don't habitually code, myself). So I wanted to lay it out for y'all in case this is a problem that you feel should be looked at. So, here's my situation. Using dovecot-1.0.rc10 downloaded from dovecot.org. Built an RPM locally on my machine (as opposed to prior attempts, which used the AT rpms), which is running RHEL 4AS with all updates. Did *not* configure in postgres, mysql, sqlite, ldap-auth. Other than that, stock (openssl included, eg) - some file locations taken from AT RPMs' spec (redhat specific file locs). No patches performed. SPEC available if y'all think it'd help; the RPM built with no complaints, installed same. Using Maildir format, upgraded from a Courier install, so .folder.subfolder structure. Error behavior: When a user attempted to open a folder containing large numbers of messages (roughly 100k+ messages, as far as we can tell) they immediately got an error saying the server has disconnected. On the server side, I got this in the log (hostname 'magneto' obviously) ---cut--- Nov 1 15:18:16 magneto dovecot: IMAP(joeuser): file mail-cache-fields.c: line 26: unreached Nov 1 15:18:16 magneto dovecot: child 17599 (imap) killed with signal 6 ---cut--- Now, the folder in question is a folder of CVS commit messages (hence the size). If I go into the folder ("/home/joeuser/Maildir/.GNOME CVS commits/") and do 'rm -f dovecot-*' and then have the user try again, then they can open the folder and get a message list. dovecot will rebuild the various index files. However, as soon as they click on an individual message, bam, the same error behavior - and from then on, they can't get into the folder again unless we remove their dovecot files again. We tried this using Evolution, mutt and pine as the clients. All exhibited identical behavior. This is coming over TLS. NOW THE FIX: I made a change to the source (gasp!) that honestly I have no idea the ramifications of, but it has...well, not *fixed*, but sorta fixed it. As per Hans Morten Kind, I commented out the i_unreached() call in field_has_fixed_size(). After this, the mail is readable as is the folder list, but now there is an error message in the log. First things first, here's the change I made to dovecot-1.0.rc10/src/lib-index/mail-cache-fields.c: ---cut--- @@ -23,7 +23,7 @@ return FALSE; } - i_unreached(); +/* i_unreached(); */ return FALSE; } ---cut--- ...and here's what now happens in the log, to the same mail folder as above: ---cut--- Nov 1 15:59:42 magneto dovecot: IMAP(joeuser): Corrupted index cache file /home/joeuser/Maildir/.GNOME CVS commits/dovecot.index.cache: field header names corrupted ---cut--- At that point, I deleted the cache files again, and the error goes away. I also notice that the index.cache file in that folder is much, much larger than it was, from which I posit that the above error was because the crashing imap process had left an incomplete index file. Removing it thus forced a rebuild with the new code which seems to have fixed the problem. Thank you all for your patience. I hand this willingly over to the list. jb -- ------------------------------------ J.B. Zimmerman jbz(a)ximian.com Network Administrator Ximian - http://www.ximian.com ...a tiny little division of Novell.

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[Dovecot] Real and Virtual Users + Domains
by Gerard Seibert 01 Nov '06

01 Nov '06

I have seen a few suggestions on how to address the issue of a system employing both real and virtual users and domains. Is there any definitive solution as to how this should be accomplished? The system I am construction will have several hundred users, both real and virtual, and probably seven domains. I plan on using MySQL to handle the user names and passwords. -- Gerard "Seen it all, done it all, can't remember most of it." Anonymous

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[Dovecot] Upgrade from RC7 to RC10 didn't go too well...
by Dominic Lepiane 01 Nov '06

01 Nov '06

Hi, On the weekend I tried to upgrade from RC7 to RC10. Clearly, I have to change some things before I can do this. What does it take to get to RC10? As is, my mail client got an error trying to list messages in /INBOX (via IMAP) and the mail.err log shows the following messages: Oct 29 10:27:32 siona dovecot: IMAP(archangel): open(/var/mail/archangel/inbox, O_CREAT) failed: Not a directory Oct 29 10:27:32 siona dovecot: IMAP(archangel): mkdir_parents(/var/mail/archangel/.imap/INBOX) failed: Not a directory Oct 29 10:27:32 siona dovecot: IMAP(archangel): open() failed with subscription file /var/mail/archangel/.subscriptions: Not a directory My dovecot.conf includes default_mail_env = mbox:/var/mail/%u And other then enabling SSL, I've got a pretty vanilla configuration (e.g. nothing in the IMAP section at all, no odd namespaces...) /var/mail/archangel is an mbox file, why is dovecot trying to open files under there? I know at least part of the discussion has happened on the list before so I'm sorry for duplicating other questions. My TODO is about ten km long so I hope someone can at least give me a couple good pointers. Thanks in advance! -- Dominic Lepiane The IRMACS Centre

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[Dovecot] Dovecot delivery
by Hr. Daniel Mikkelsen 01 Nov '06

01 Nov '06

Hi. Does the dovecot deliver helper program now support maildirs? Are there plans to support this? -- Daniel Mikkelsen Copyleft Software AS

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Re: [Dovecot] Redundant shared mail store?
by Joshua Goodall 01 Nov '06

01 Nov '06

dovecot(a)redigloo.org wrote: > My ears prick up whenever I hear mention of NetApps and Dovecot. > > Which operating system (Linux, Solaris, Solaris x86...) are you > running. The NFS clients w/Dovecot are currently running Linux 2.6.16 with Trond Myklebust's Linux-2.6.16-NFS_ALL.dif applied (see http://client.linux-nfs.org/) This combo has been stable for months. And yes, we use fcntl locking, and mount noac,actimeo=0. JG

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[Dovecot] moving public folders to private Trash
by Mark Nienberg 01 Nov '06

01 Nov '06

Using Thunderbird 1.5.0.4 against dovecot beta9: If a user has Thunderbird configured to move deleted messages into a Trash folder, then the user cannot delete folders in a public namespace. There is no problem deleting messages. Thunderbird says: "The current command did not succeed. The mail server responded: Can't rename mailbox to another storage type." All mailboxes (public and private) are maildir format. Users can successfully delete folders from their own private areas, and the folders then appear as subfolders of the Trash folder. Also, users can reconfigure Thunderbird to delete messages immediately instead of moving them to trash and then successfully remove public folders. Also, users can move public folders within the public namespace. So I think the problem boils down to the inability to move a folder from a public namespace to a private one, which is what happens when Thunderbird is configured to move deleted messages to a Trash folder. Mark Nienberg

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[Dovecot] IMAP Dovecot with ISPConfig and shared folders?
by Perry 31 Oct '06

31 Oct '06

Fedora 5, postfix, dovecot, ISPConfig server all running well, (don't want to break it) LOL. But, I do not have IMAP shared folders. These instructions on dovecot tell of how to setup namespace to be able to get shared folders. http://wiki.dovecot.org/SharedFolders But given everything is relative in ISPConfig, not sure if this is possible or if I could really mess things up. What tells dovecot to look in the various different web# folders for email? Am I better off using Symlinking??? Thanks much for all comments and direction. ____________________________________________________________________________________ Cheap Talk? Check out Yahoo! Messenger's low PC-to-Phone call rates (http://voice.yahoo.com)

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Re: [Dovecot] Redundant shared mail store?
by Joshua Goodall 31 Oct '06

31 Oct '06

Jasper Bryant-Greene wrote: > Hi guys > > I'm about to embark on a project replacing a legacy single mail server > running proprietary software with a cluster of Dovecot servers. We > clearly need a shared mail store for these servers, but we are not happy > with simply using a server running NFS as this becomes a single point of > failure. > > What have other people used? AFAICT our options are: > > * A shared block device (Fibre Channel, iSCSI, ATAoE etc) running > GFS > or similar to allow multiple servers to access it concurrently > > * Two or more NFS units, either with built-in support for > replication > of FS changes and failover, or with scripts for achieving this > functionality > > I prefer option 1, although it's expensive. What have other people used? > Do we have other options? I recommend a pair of NetApp filers (e.g. 2 x 3020c) exporting NFS from shared disk shelves in their high-availability mode. This is a hybrid of the two options, except a) it's a fully supported and stable NetApp configuration, b) they're sharing disk storage, c) you're not hog-tied to GFS, d) it's the best NFS implementation in the world (you can even trust the fcntl locking), e) it's really fast, f) NetApp's onboard snapshots and other funky software bits will make you wonder how you lived without them, g) the HA actually works. I have a six-digit userbase with mailboxes in this configuration. JG

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