- dovecot - dovecot.org

[Dovecot] coding techniques
by David Lee 09 Oct '06

09 Oct '06

Whilst debugging a problem in dovecot LDA over the last few days, I came across two different issues in coding techniques. (Note: Please don't take this negatively; my intent is both positive and constructive!) The front page of the website www.dovecot.org says: "it uses several coding techniques to avoid most of the common pitfalls" So I hope it is OK to follow the spirit of that with some suggestions. The two issues I encountered both seem to be fairly easy holes to fall into, and yet equally easy to avoid in the first place by using established C practices. Firstly, many 'if' statements having a single statement (whether in then or else part) are currently written in a short-cut fashion: if (condition) statement 1; else statement 2; This, though technically legal, is potentially lethal when inserting (say) debugging statements. Without diligence it is all to easy to produce: if (condition) debug 1a; statement 1; debug 1b; else debug 2a; statement 2; debug 2b; A simple edit that looks, layout-wise, as if it would do the right thing (and do in Python!); but actually radically changes the execution flow. (This is left as an exercise to the reader... to demonstrate the point.) Could I suggest that the relevant brackets be always used as a matter of course? Something like: if (condition) { statement 1; } else { statement 2; } Then the insertion of debug statements doesn't inflict surprise. (No, I didn't fall into this hole. But it is a trap waiting to happen.) Secondly, code duplication. To give one example: 'get_var_expand_table()' appears in both 'deliver/deliver.c' and 'master/mail-process.c'. (There is also a similar looking function in 'auth/auth-request.c'.) Perhaps consideration should be given to merging such instances. For instance, my woes with "%i"-expansion being treated differently in mail-reading and mail-delivery would likely never have arisen if common code had been used. I hope that helps (constructively!). Best wishes. -- : David Lee I.T. Service : : Senior Systems Programmer Computer Centre : : Durham University : : http://www.dur.ac.uk/t.d.lee/ South Road : : Durham DH1 3LE : : Phone: +44 191 334 2752 U.K. :

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[Dovecot] rc7 crashing under heavy load
by Jeff A. Earickson 09 Oct '06

09 Oct '06

Help! Our students are back and they are pounding my dovecot server to death (ie "Login process died too early - shutting down" or "too many open files" type crash). I've had my third crash today. My setup: Solaris 10, imap and imaps, 3K users coming in via horde webmail. My current connection settings are: login_max_processes_count = 2048 login_max_connections = 4096 Q: Does raising these limits actually make my problem worse or better? Are there any other variables that I should change to prevent the "too many open files"? Suggestions? Jeff Earickson Colby College

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[Dovecot] sent message not always saved in imap sent folder
by Ian Mortimer 09 Oct '06

09 Oct '06

Users who have their sent folder on the imap server report that sometimes a sent message is saved locally instead of on the server. This is the error from evolution: Error while performing operation. Failed to append to whoever@imap.server:Sent: Server unexpectedly disconnected: Unknown error Appending to local `Sent' folder instead.. We're seeing this with more than one client: evolution (linux) and thunderbird (OS X). It only happens occasionally but often enough to be annoying. It could be because the user's Sent folders are in their home directories which are NFS mounted. Are there any dovecot settings which might help? Thanks -- Ian

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[Dovecot] Lost email (inbox) TWICE
by Sezer Yalcin 09 Oct '06

09 Oct '06

I have been losing my inbox. It happened twice. (2 days ago and just half an hour ago) I am using RHEL 4.0 with dovecot-0.99.11-4.EL4 System uses sendmail + procmail, dovecot is up and running. Here is how it happened: I was using Mozilla Firefox with IMAP. At the same time, I logged in from Squirrel Webmail in IMAP to the same account. Squirrel mail did not show my inbox contents. And I turned back to Thunderbird and it said, ' an error has occurred and logged to system log' and INBOX WAS LOST! squirrelmail 1.4.6 and mozilla thunderbird version 1.5.0.7 I checked server log, I see I log in but there are no further logs. This happened 2 days ago, I was wondering what the hell happened. I did not have any issues before. However recently we had a hard drive crash and all home folders are restored from backups. I assume it can be related to this. My inbox and imap folders are all in mbox format. I believe dovecot could not write to log or had something unexpected which lead to loss of inbox. There were no configuration issues and all mail system including dovecot were working fine. Now it works fine as well, but I believe it will lose inbox folder again. Has anybody experienced this? Any suggestions to recover inbox? File was reset to 0 bytes (could be deleted as well), when i did 'stat' on file, there was a file with 1 new message, all were lost. Thank you. Sezer

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[Dovecot] Dovecot hang
by Catalin Constantin 09 Oct '06

09 Oct '06

Hello, We run dovecot 1.0.rc6-1 on a debian system. The user auth db is postgresql and the storage folders are on a NFS partition. Latelly every 2 days the authentification hangs and i see in the logs: Sep 21 10:04:22 c005 dovecot: login: tried to change state 0 -> 17808 (if you can't login at all, see src/lib/fdpass.c) What is the problem ? What can i do ? Thank you ! -- Catalin Constantin Bounce Software http://www.bounce-software.com http://www.cabanova.ro

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Re: [Dovecot] LIST command ignores "hidden=yes" for default namespace
by Bill Boebel 09 Oct '06

09 Oct '06

On Sun, August 6, 2006 7:57 pm, Timo Sirainen <tss(a)iki.fi> said: > On Wed, 2006-07-05 at 12:04 -0400, Bill Boebel wrote: >> On Sun, June 11, 2006 1:51 pm, Timo Sirainen <tss(a)iki.fi> said: >> > On Mon, 2006-05-08 at 22:03 -0400, Bill Boebel wrote: >> >I'm not sure if this is a bug or just an undesirable feature, but when I >> >have our namespace configured to match Courier's "INBOX." functionality, >> >Dovecot forces me to also define a default namespace (with no prefix). >> >Without the default namespace defined I get "NO Unknown namespace." errors >> >when trying to subscribe or unsubscribe folders. >> > >> > It was a bug when tb-extra-mailbox-sep workaround was enabled. Fixed: >> > http://dovecot.org/list/dovecot-cvs/2006-June/005709.html >> > >> >> The second part of this still seems to be the case with RC2... the LIST command >> ignores "hidden=yes". > > hidden=yes only means it's not listed in NAMESPACE command's reply and > that the namespace prefix isn't shown as a mailbox in LIST replies. > Since the prefix is empty and you're listing the mailboxes from root, it > shows the mailboxes as it should.. > > Correct way would be to just use one namespace and fix the problems > related to it. Could you test with RC6 and show me what commands give > the unknown namespace errors? Subscribing and unsubscribing worked fine > with me. Although INBOX subscription causes some problems with LSUB. > I finally got around to testing this. I tested with RC7 CSV 20060924. And I am testing with just one namespace: namespace private { separator = . prefix = INBOX. inbox = yes } I no longer get the unknown namespace errors. However, INBOX is listed twice in the LIST command: 2 list "" "*" * LIST (\HasChildren) "." "INBOX" * LIST (\HasChildren) "." "INBOX.RSS" * LIST (\HasNoChildren) "." "INBOX.Sent" * LIST (\HasNoChildren) "." "INBOX.Test" * LIST (\HasNoChildren) "." "INBOX.spam" * LIST (\HasNoChildren) "." "INBOX.Trash" * LIST (\HasNoChildren) "." "INBOX.Drafts" * LIST (\HasNoChildren) "." "INBOX" * LIST (\HasNoChildren) "." "INBOX.RSS.Kevin Minnick" If I change the namespace's inbox setting to "inbox = no" it only lists the INBOX once, however subscribing to the INBOX gives the "Unknown namespace." error. 2 list "" "*" * LIST (\HasChildren) "." "INBOX" * LIST (\HasChildren) "." "INBOX.RSS" * LIST (\HasNoChildren) "." "INBOX.Sent" * LIST (\HasNoChildren) "." "INBOX.Test" * LIST (\HasNoChildren) "." "INBOX.spam" * LIST (\HasNoChildren) "." "INBOX.Trash" * LIST (\HasNoChildren) "." "INBOX.Drafts" * LIST (\HasNoChildren) "." "INBOX.RSS.Kevin Minnick" 2 OK List completed. 4 subscribe INBOX 4 NO Unknown namespace.

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[Dovecot] Using NFS - which OS would you chose
by Jonathan 09 Oct '06

09 Oct '06

Hi, I'm still looking at a large (under 100,000) user deployment of Dovecot, with a NetApp NFS server as the back-end storage. I've read a few remarks about needing the latest NFS patches from Trond Myklebust to prevent lock-ups. My management would be happiest with a vendor-supported distribution (and especially Suse Linux Enterprise Server 9 or 10). We will be running on an x86 platform. Under these circumstances, which operating system/distribution would you choose? And why? Suse SLES9 OpenSuse Debian RedHat FreeBSD Solaris_x86 Nexenta (www.nexenta.org) Many thanks for your thoughts/war stories. Jonathan.

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[Dovecot] Cache fields
by Tony Kay 09 Oct '06

09 Oct '06

Hi, We are using Dovecot with maildir, and the mail client requests flags, internaldate, and uid for all messages on folder open, which on average takes 3 seconds, but for large folders is much longer. It seems like I want mail_cache_fields to include "flags", but which date corresponds to internaldate? date.received? Is UID always cached for messages, or does it have to read through the directory to get them? Are there other optimizations I can do that will improve the speed of folder opens? -- Anthony Kay University Computing Center (541) 346-1719 GPG Fingerprint: B0DB D46A 60AF FAE7 A94A 5075 0CB4 4D88 9F4F 7F09 This isn't right. This isn't even wrong. Wolfgang Pauli

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[Dovecot] Date Received question
by Timothy Martin 09 Oct '06

09 Oct '06

I migrated from Courier to Dovecot, and today I notice that all my "date received" fields in my client (apple mail) show as the approx date/time of the migration rather than when the emails were received from the smtp server. Is this expected behavior? I normally sort by received date rather than sent -- since I don't care when someone sends something as much as when i get it. But those fields are totally bogus now. .tim

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[Dovecot] Tru64 Unix and SIA
by Simon L Jackson 09 Oct '06

09 Oct '06

I have recently written a (minimal) Tru64 Unix SIA password module for Dovecot as part of testing a Dovecot installation. Has anyone else written a Tru64 Unix SIA module? Is anyone else interested in such a module? If so, how might I/we go about getting this/such a module into the main Dovecot source? Thanks -- Simon L Jackson Carringbush.Net +- Carringbush.Net Hosting * Development * Advice Web: www.carringbush.net <http://www.carringbush.net/> Email: simon.jackson(a)carringbush.net <mailto:simon.jackson@carringbush.net> Office: +61 3 9411 4400 Support: +61 3 9411 4444 Fax: +61 3 9411 4499 Level 1 15 Bedford Street Collingwood VIC 3066 Australia P.O. Box 1464 Collingwood VIC 3066 Australia +-

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