- dovecot - dovecot.org

[Dovecot] Performance, dovecot vs tpop3d
by Nate 01 Feb '07

01 Feb '07

Hello, I am new to the list and have spent extensive time researching performance suggestions through the list and the documentation. Particularly interesting is the recent performance thread related to the upcoming release. I just upgraded one of our email servers from tpop3d to dovecot 1.0rc19. tpop3d has served us well for many years; however, it basically has lost all it's support and developers. My main liking of tpop3d was it's speed. After the upgrade to dovecot, the server began to crawl. This server runs postfix for the delivery agent and now dovecot for pop3 and imap. The box serves roughly 9000 virtual maildir mailboxes with roughly 20 pop3 processes active at any given time. I ran some tests this morning to determine an exact difference between running tpop3d and dovecot. dovecot: I/O load averages 81%, System load averages 12.00 tpop3d: I/O load averages 20%, System load averages 0.50 To ensure it wasn't just a fluke of logins, I let each app run for several minutes, and did the test multiple times. The results were not any abnormal user usage and definitely related to application performance. My current settings in dovecot related to performance are: mmap_diable = yes mmap_no_write = yes Modifying these to no seems to decrease performance slightly but only a few percent. I have also played with various other settings, which didn't give me any significant performance boost. I'm eager for the next release which will have the fsync_disable option to see if that helps, it certainly looks promising. One observation where the majority of the load seems to be generated from is when a pop3 connection is loading up a very large maildir. The pop3 process seems to remain around using I/O for a considerable time, even when the user has no new email. Perhaps it is rebuilding or verifying it's index files? Here is an example of a lsof of the pop3 process with a user who has roughly 17000 messages. They check their email every 10 minutes which seems to add significant load. Note the final line, it's reading an individual message file, yet the user has no new email since the last login. If i keep lsofing the process, the final file seems to change and keep going through many of their mailbox files. The process takes many minutes to complete. Is it rebuilding the index on every login? COMMAND PID USER FD TYPE DEVICE SIZE NODE NAME pop3 15148 postfix cwd DIR 9,2 152 850160 /home/domain.net/brock pop3 15148 postfix rtd DIR 9,2 816 2 / pop3 15148 postfix txt REG 9,2 1888690 7096106 /usr/local/libexec/dovecot/pop3 pop3 15148 postfix mem REG 9,2 107724 182934 /lib/ld-2.3.2.so pop3 15148 postfix mem REG 9,2 1578228 182936 /lib/tls/libc-2.3.2.so pop3 15148 postfix mem REG 9,2 16312 88977 /lib/libdl-2.3.2.so pop3 15148 postfix 0u IPv4 873280915 TCP domain.net:pop3->dsl.dyn.06-99.uslogin.net:40950 (CLOSE_WAIT) pop3 15148 postfix 1u IPv4 873280915 TCP domain.net:pop3->dsl.dyn.06-99.uslogin.net:40950 (CLOSE_WAIT) pop3 15148 postfix 2w FIFO 0,5 873280916 pipe pop3 15148 postfix 3r CHR 1,9 27963 /dev/urandom pop3 15148 postfix 4r FIFO 0,5 873281456 pipe pop3 15148 postfix 5w FIFO 0,5 873281456 pipe pop3 15148 postfix 6r FIFO 0,5 873281457 pipe pop3 15148 postfix 7w FIFO 0,5 873281457 pipe pop3 15148 postfix 8u REG 9,2 205740 7272682 /var/spool/mail/domain.net/brock/dovecot.index pop3 15148 postfix 9u REG 9,2 15020 7225137 /var/spool/mail/domain.net/brock/dovecot.index.log pop3 15148 postfix 10u REG 9,2 1585152 7290906 /var/spool/mail/domain.net/brock/dovecot.index.cache pop3 15148 postfix 11r REG 9,2 1992 5040734 /var/spool/mail/domain.net/brock/cur/1165164651.V902I4cea5e.s3.visp.net:2,S I'm eager to solve this new I/O issue which has cropped up after upgrading to dovecot. Despite the severe performance degradation, I feel dovecot has awesome potential and is feature rich, and most importantly it's being maintained, so I want to stick with it! Thank you for any help offered! I'm hopeful for any suggestions to solve this performance issue or diagnose it further to determine the cause. - Nate

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[Dovecot] Making POP3 not retrieve deleted messages
by Aredridel 01 Feb '07

01 Feb '07

Since my users often use the webmail system to delete messages to save their poor strained dial-up POP3-using mail clients, and our new web mail system isn't expunge-happy like the last one, I found need for this patch -- it adds a configuration option for pop3 "pop3_ignore_deleted", a boolean, that does just that. I'd love feedback. Aria

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[Dovecot] Mail Answered status flag in pine stopped working in rc19
by Carl Mason --- Director Demography Lab 31 Jan '07

31 Jan '07

The Flag indicating that a message has been Answered does not work in pine. The status flags for New and Deleted work as always. The Answered flag worked properly in dovecot 0.99, but after upgrading to 1.0rc19 it stopped working. Interestingly, mail that was answered before upgrading to rc19 still shows the proper flag. I have tried with mbox_dirty_syncs turned on and off and I have tried putting "flags" in mail_cache_fields. Obviously I am wandering in the dark. Here is the setup: pine 4.64 dovecot 1.0rc19 (installed from rpm dovecot-1.0-2_40.rc19.el4.at.i386.rpm) Centos 4.4.2 x86 mail_location = mbox:~/mail/:INBOX=%h/.mailspool/%u:INDEX=/var/dovecot_indexes\/%d/%n Inbox is NFS mounted, INDEX is on local disk Thanks.

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Re: [Dovecot] Performance, dovecot vs tpop3d
by Nate 31 Jan '07

31 Jan '07

At 09:01 PM 1/30/2007, Curtis Maloney wrote: >Nate wrote: >>Perhaps another test i'll run, just to compare apples to apples >>tomorrow would be to use a memory index with dovecot as well, and >>see if that drops the I/O load to the same as when tpop3d is running. > >Speaking of "Apples to Apples", you might want to try with >INDEX=MEMORY on Dovecot, see how that fares. > >If your users are only POP3 and download all messages at once, not >keeping mail on the server, you can (iirc) disable indexing >altogether, since it's a wasted effort. That test was on my list to try out today. I ran the test, and performance was severely degraded. Upon every new login, the entire index was rebuilt. So with any login it takes the full ~30 seconds to rebuild the index on a 17000 email user. I've confirmed also that tpop3d is doing no indexing whatsoever on disk. It isn't even compiled with that option. So it seems it is probably disk caching which is assisting tpop3d with returning a 2nd login (within a few minutes) so quickly. I wish it were the case that all users downloaded messages, but it seems all too often users click the 'leave messages on server', and never expire them. We have quite a few users (thousands probably) in that condition. We occasionally delete old stuff. Did I hear about an expire plugin upcoming? That would be useful. - Nate

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[Dovecot] Sieve and LDA
by Vincent Bernat 31 Jan '07

31 Jan '07

Hello ! I have started to use Sieve support in LDA. From the RFC a same message should not be delivered twice in the same folder : ,---- | 2.10.3. Message Uniqueness in a Mailbox | | | Implementations SHOULD NOT deliver a message to the same folder more | than once, even if a script explicitly asks for a message to be | written to a mailbox twice. | | The test for equality of two messages is implementation-defined. | | If a script asks for a message to be written to a mailbox twice, it | MUST NOT be treated as an error. `---- Dovecot seems to ignore this "SHOULD NOT" or am I missing something ? At first, I thought they were speaking of case where there is two idententic "fileinto" directive in the ruleset. Something like : fileinto "box"; fileinto "box"; But, I don't think that they would they "the test for equality of two messages" with such a trivial case. Maybe dovecot should maintain a list of recent message-id seen for each user (with the associated mailbox). -- I WILL ONLY DO THIS ONCE A YEAR I WILL ONLY DO THIS ONCE A YEAR I WILL ONLY DO THIS ONCE A YEAR -+- Bart Simpson on chalkboard in episode 3F31

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[Dovecot] IMAP on move message command launch
by Jan Srzednicki 31 Jan '07

31 Jan '07

Hello, Is it possible with dovecot IMAP server to do the following thing: After the clients moves a message from any folder to the given one, I want to launch a command and feed that message into it, as well as physically move the message to this folder. Is that possible? -- Jan Srzednicki w(a)expro.pl

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[Dovecot] Need help with "mbox sync" problem
by Jim Garrison 31 Jan '07

31 Jan '07

The following is occurring consistently on users in only one vhost domain. Other vhost domains are not having the problem. The email client in use is the same (in both the working and non-working domains). dovecot: Jan 29 21:19:18 Error: POP3(user1(a)mydomain.tld): mbox sync: UID inserted in the middle of mailbox /var/mail/vhosts/mydomain.tld/user1 (5629 > 5423, seq=2, idx_msgs=5) dovecot: Jan 29 21:19:18 Info: POP3(user1(a)mydomain.tld): Disconnected: Logged out top=0/0, retr=95/508506, del=95/95, size=506866 dovecot: Jan 29 21:19:52 Error: POP3(user2(a)mydomain.tld): mbox sync: UID inserted in the middle of mailbox /var/mail /vhosts/mydomain.tld/user2 (5634 > 5629, seq=2, idx_msgs=95) dovecot: Jan 29 21:19:52 Info: POP3(user2(a)mydomain.tld): Disconnected: Logged out top=0/0, retr=5/69654, del=5/5, si ze=69562 Once this message starts occurring, dovecot stops deleting retrieved messages when the user retrieves mail (with 'delete from server' set). The result is that the entire mailbox contents are fetched each time, resulting in copious amounts of duplicate messages. I'm on the rc8 RPM that comes with FC5, but am willing to remove it and install a later Dovecot built from source. 1) Is this a known problem that can be fixed by upgrading? 2) If not, can someone tell me what this message means exactly, and how to gather more information for debugging? The MTA is Postfix. Thanks

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[Dovecot] OT:install dovecot using yum
by jepoy 31 Jan '07

31 Jan '07

hi guys, im trying to install dovecot using yum on my centos. anyone tried this? tnx -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

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Re: [Dovecot] Dovecot ACL
by Radek Zavicak 31 Jan '07

31 Jan '07

>I am using 1.0-rc19 version. I made a global ACL file in >/etc/dovecot-acls/Public as: >owner lrsi >user=manager rl > >The owner cannot delete/move mail inside his Public folder as I want. But >the user "manager" cannot subscribe/view to other's Public folder. What I >have missed? Make sure your acl file ends with LF (there is an empty line at the end) otherwise dovecot doesn't read the last line.

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[Dovecot] Fw: error after installation
by jepoy 31 Jan '07

31 Jan '07

----- Original Message ----- From: "jepoy" <jcb(a)dream.com.ph> To: <lrosa(a)hypertrek.info> Sent: Wednesday, January 31, 2007 1:43 PM Subject: Re: [Dovecot] error after installation > > ----- Original Message ----- > From: "Luigi Rosa" <lrosa(a)hypertrek.info> > To: "Dovecot Mailing List" <dovecot(a)dovecot.org> > Sent: Wednesday, January 31, 2007 1:26 PM > Subject: Re: [Dovecot] error after installation > > >> jepoy said the following on 31/1/2007 6:22: >> >>> -ERR Plaintext authentication disallowed on non-secure connections. >> >> check dovecot.conf for >> >> disable_plaintext_auth = no >> >> >> Ciao, >> luigi >> > hi luigi, > thanks for that quick response. here's my next problem.before i havent > encountered them when i use yum. > > +OK Dovecot 1.0 ready. > user jcb > +OK > pass jcb > -ERR Authentication failed. > > tnx > -- This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean.

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