[Dovecot] dovecot performance question
Hi, using the latest dovecot with pop3/imap. Using mostly outlook 2003 for pop3 and squirrel mail imap.
I have a lot of users reporting back that imap is very slow. We average about 300 imap and another 700 pop session at any given time.
Here's my config:
disable_plaintext_auth: no login_dir: /usr/local/var/run/dovecot/login login_executable(default): /usr/local/libexec/dovecot/imap-login login_executable(imap): /usr/local/libexec/dovecot/imap-login login_executable(pop3): /usr/local/libexec/dovecot/pop3-login login_greeting: Cape.Com D-V.1 ready. login_processes_count: 14 max_mail_processes: 9000 mail_location: maildir:/home/%1u/%u/Maildir mail_executable(default): /usr/local/libexec/dovecot/imap mail_executable(imap): /usr/local/libexec/dovecot/imap mail_executable(pop3): /usr/local/libexec/dovecot/pop3 mail_plugin_dir(default): /usr/local/lib/dovecot/imap mail_plugin_dir(imap): /usr/local/lib/dovecot/imap mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %v.%u pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh auth default: count: 4 passdb: driver: pam userdb: driver: passwd
I'm trying to figure out what im doing wrong, I was seeing the same performance issues with .99.
Here's what im seeing for connections,
[root@pop etc]# ps aux | grep pop3 | wc -l 562 [root@pop etc]# ps aux | grep imap | wc -l 254 [root@pop etc]#
I am having a time issue on this server and im not sure if its affecting dovecot.
May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:31 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:42 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present.
Thanks,
P
I had this problem when running under vmware (time slippage). I took vmware out of the loop and all is well.
Also, you should be using ntpd, not cron and ntpdate -b.
Paul A wrote:
Hi, using the latest dovecot with pop3/imap. Using mostly outlook 2003 for pop3 and squirrel mail imap.
I have a lot of users reporting back that imap is very slow. We average about 300 imap and another 700 pop session at any given time.
Here's my config:
disable_plaintext_auth: no login_dir: /usr/local/var/run/dovecot/login login_executable(default): /usr/local/libexec/dovecot/imap-login login_executable(imap): /usr/local/libexec/dovecot/imap-login login_executable(pop3): /usr/local/libexec/dovecot/pop3-login login_greeting: Cape.Com D-V.1 ready. login_processes_count: 14 max_mail_processes: 9000 mail_location: maildir:/home/%1u/%u/Maildir mail_executable(default): /usr/local/libexec/dovecot/imap mail_executable(imap): /usr/local/libexec/dovecot/imap mail_executable(pop3): /usr/local/libexec/dovecot/pop3 mail_plugin_dir(default): /usr/local/lib/dovecot/imap mail_plugin_dir(imap): /usr/local/lib/dovecot/imap mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %v.%u pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh auth default: count: 4 passdb: driver: pam userdb: driver: passwd
I'm trying to figure out what im doing wrong, I was seeing the same performance issues with .99.
Here's what im seeing for connections,
[root@pop etc]# ps aux | grep pop3 | wc -l 562 [root@pop etc]# ps aux | grep imap | wc -l 254 [root@pop etc]#
I am having a time issue on this server and im not sure if its affecting dovecot.
May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:31 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:42 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present.
Thanks,
P
Jason, im also using virtual server software from virtual iron. I will be also moving this off the virtual server and on to a dell 1900. Did you notice better performance once you moved away from vmware ?
Thanks, Paul
-----Original Message----- From: dovecot-bounces@dovecot.org [mailto:dovecot-bounces@dovecot.org] On Behalf Of Jason Godsey Sent: Tuesday, May 29, 2007 10:19 PM To: dovecot@dovecot.org Cc: Paul A Subject: Re: [Dovecot] dovecot performance question
I had this problem when running under vmware (time slippage). I took vmware out of the loop and all is well.
Also, you should be using ntpd, not cron and ntpdate -b.
Paul A wrote:
Hi, using the latest dovecot with pop3/imap. Using mostly outlook 2003 for pop3 and squirrel mail imap.
I have a lot of users reporting back that imap is very slow. We average about 300 imap and another 700 pop session at any given time.
Here's my config:
disable_plaintext_auth: no login_dir: /usr/local/var/run/dovecot/login login_executable(default): /usr/local/libexec/dovecot/imap-login login_executable(imap): /usr/local/libexec/dovecot/imap-login login_executable(pop3): /usr/local/libexec/dovecot/pop3-login login_greeting: Cape.Com D-V.1 ready. login_processes_count: 14 max_mail_processes: 9000 mail_location: maildir:/home/%1u/%u/Maildir mail_executable(default): /usr/local/libexec/dovecot/imap mail_executable(imap): /usr/local/libexec/dovecot/imap mail_executable(pop3): /usr/local/libexec/dovecot/pop3 mail_plugin_dir(default): /usr/local/lib/dovecot/imap mail_plugin_dir(imap): /usr/local/lib/dovecot/imap mail_plugin_dir(pop3): /usr/local/lib/dovecot/pop3 pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %v.%u pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh auth default: count: 4 passdb: driver: pam userdb: driver: passwd
I'm trying to figure out what im doing wrong, I was seeing the same performance issues with .99.
Here's what im seeing for connections,
[root@pop etc]# ps aux | grep pop3 | wc -l 562 [root@pop etc]# ps aux | grep imap | wc -l 254 [root@pop etc]#
I am having a time issue on this server and im not sure if its affecting dovecot.
May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:31 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present. May 29 11:42:42 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until w e're back in present.
Thanks,
P
This is is follow up to my previous post about dovecot performance being slow.
BTW, thanks to all that replied.
For one month we have been trying to figure why suddenly dovecot was slow. We had two server's running dovecot with the same config and one was fine while the other wasn't very slow. The server that was slow was on a virtual server and we noticed some time errors in the logs and installed ntpd which didn't help the problem.
After trying to tweak the config etc... I put dovecot on a new server and its running great.
Before I was seeing 35% idle cpu with 700 + pop3 login sessions and another 400 imap. Since we moved to a new server, that has no time issues, we are seeing 97% idle cpu with 50 - 70 pop3 logins and 40 imap while performance is a lot faster.
The previous system, giving us all the problems, was on a virtual server running Virtual Iron software. The hardware was the same on both.
Here's what I was seeing, that contributed to the problems causing 7000 angry customers to call us :)
[root@pop etc]# ps aux | grep pop3 | wc -l 740 [root@pop etc]# ps aux | grep imap | wc -l 450 [root@pop etc]#
May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until we're back in present. May 29 11:42:19 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until we're back in present. May 29 11:42:31 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until we're back in present. May 29 11:42:42 pop dovecot: POP3(xxx): Time just moved backwards by 1 seconds. I'll sleep now until we're back in present.
I was also getting postfix "backwards time" errors. I guess these errors were causing login sessions to stay up longer then they should have which backed up my server. I hope this helps someone out sooner as I had a feeling the time was causing the problems but mgt here didn't let me try to move it to another server until they exhausted all other options.
Thanks,
Paul
participants (3)
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Jason Godsey
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Paul A
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Paul Amaral