On Sun, Oct 26, 2008 at 9:54 AM, Timo Sirainen tss@iki.fi wrote:

On Sun, 2008-10-26 at 09:45 -0700, Brandon Lamb wrote:

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Anyway, the reason for this post is that I have seen these pop up in my logs, and on one of my mailheads there were some 50 lines of this

But it doesn't happen all the time?

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dovecot: 2008-10-26 09:33:54 Error: auth(default): BUG: Authentication client gave a PID 15661 of existing connection

Does it log anything else than this? Are you running multiple Dovecots? Post your dovecot -n output?

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I am using Debian lenny/sid on amd64,

Is it a standard Debian/kernel.org kernel or have you done some modifications? This isn't a virtual machine?

I have four amd64 boxes, amd 9850, 4 gig ram, Debian lenny/sid running 2.6.26-1-amd64, using LVS to load balance pop3, imap, smtp traffic. NFS mailstore, 2 gige cards, eth1 being the private nfs backend network, eth0 is what talks to the world.

dovecot config: # 1.1.5: /etc/dovecot/dovecot.conf base_dir: /var/run/dovecot/ log_path: /var/log/dovecot/dovecot.log info_log_path: /var/log/dovecot/info.log log_timestamp: %Y-%m-%d %H:%M:%S protocols: imap pop3 listen(default): 208.200.248.2 208.200.248.7 listen(imap): 208.200.248.2 208.200.248.7 listen(pop3): 208.200.248.2 disable_plaintext_auth: no login_dir: /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: Hello there. login_log_format_elements: <%u> <%r> login_log_format: %s login_process_size: 96 login_processes_count: 15 login_max_processes_count: 256 valid_chroot_dirs: /mail/mail mail_max_userip_connections(default): 15 mail_max_userip_connections(imap): 15 mail_max_userip_connections(pop3): 4 verbose_proctitle: yes first_valid_uid: 8 last_valid_uid: 8 first_valid_gid: 8 last_valid_gid: 8 mail_access_groups: mail mail_privileged_group: mail mail_uid: 8 mail_gid: 8 mail_location: maildir:~/:INDEX=/dovecot-index mailbox_idle_check_interval: 60 mail_save_crlf: yes mmap_disable: yes mail_nfs_storage: yes mailbox_list_index_disable: no 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_plugins(default): quota imap_quota mail_plugins(imap): quota imap_quota mail_plugins(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 mail_log_prefix: %Ls <%u>: imap_client_workarounds(default): outlook-idle delay-newmail imap_client_workarounds(imap): outlook-idle delay-newmail imap_client_workarounds(pop3): pop3_no_flag_updates(default): no pop3_no_flag_updates(imap): no pop3_no_flag_updates(pop3): yes pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh pop3_logout_format(default): top=%t/%p, retr=%r/%b, del=%d/%m, size=%s pop3_logout_format(imap): top=%t/%p, retr=%r/%b, del=%d/%m, size=%s pop3_logout_format(pop3): retr=%r/%b, del=%d/%m, size=%s auth default: mechanisms: plain login default_realm: olypen.com cache_size: 8192 cache_ttl: 300 worker_max_count: 60 passdb: driver: sql args: /etc/dovecot/dovecot-sql.conf userdb: driver: prefetch userdb: driver: sql args: /etc/dovecot/dovecot-sql.conf socket: type: listen client: path: /var/run/dovecot/auth-client mode: 438 user: mail group: mail master: path: /var/run/dovecot/auth-master mode: 438 user: mail group: mail plugin: quota: maildir quota_rule: Trash:ignore quota_rule2: Sent:ignore quota_rule3: Spam:ignore quota_rule4: Archive:ignore quota_rule5: Sent Items:ignore quota_rule6: Deleted Items:ignore auth_socket_path: /var/run/dovecot/auth-master

So the load balancer is randomly assigning the user to different servers? Not really the preferred setup. I guess you've read http://wiki.dovecot.org/NFS? Yes, in our previous setup we just used round robin and it seemed to be fine, never had load problems (using courier). After switching to dovecot I had tried both, while trying to narrow down the problem to the pop3 I had set only 1 machine to handle all pop3 and I got a call the next morning from support and the load was 511.

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login_processes_count: 15 login_max_processes_count: 256

This problem and possibly others could maybe be solved by using the high performance mode as described by http://wiki.dovecot.org/LoginProcess

I tried this the same night that I had a single pop3 box, it ran out of processes I think was what the log said, so I switched back to the current settings.

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mail_location: maildir:~/:INDEX=/dovecot-index

Are index files on local disk or on NFS?

Yes, although I set INDEX=MEMORY for pop3 section after reading that on one of the google search results

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mail_save_crlf: yes

This adds some extra disk I/O, probably better to set to "no" unless you have a good reason.

I forgot why I had enabled this, I just turned it off though.

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mmap_disable: yes mail_nfs_storage: yes

If indexes are on NFS, you should have mail_nfs_index=yes too.

I had this enabled as well until I read the index=memory thing and then disabled it. I just now turned it on again.

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mailbox_list_index_disable: no

These aren't actually always disabled since the code is buggy..

I tried searching for what this did or what it meant but didnt find anything helpful. Should I set manually set this to yes or leave it?

BTW. Are you using Dovecot's deliver for new mails?

No I am just using exim 4.69 to deliver directly to maildir

On Sun, Oct 26, 2008 at 9:54 AM, Timo Sirainen tss@iki.fi wrote:

On Sun, 2008-10-26 at 09:45 -0700, Brandon Lamb wrote:

...

Anyway, the reason for this post is that I have seen these pop up in my logs, and on one of my mailheads there were some 50 lines of this

But it doesn't happen all the time?

...

dovecot: 2008-10-26 09:33:54 Error: auth(default): BUG: Authentication client gave a PID 15661 of existing connection

Does it log anything else than this? Are you running multiple Dovecots? Post your dovecot -n output?

...

I am using Debian lenny/sid on amd64,

Is it a standard Debian/kernel.org kernel or have you done some modifications? This isn't a virtual machine?

Ive been fighting with the pop3 part of dovecot for the past 2 weeks, and I have tried and changed so many things that to be honest Im feeling a little bonkers and if you see anything obviously wrong in my config feel free to chastise me.

The error does not happen every time no, but I have been clearing the log file a lot because this system has been unstable, having high loads, running out of auth connections, I have been having chdir (/mail/mail/usersmaildir) blocked for 12 seconds, I have seen my max connectiosn for auth workers I think it was run out, that was when I had a 511 load.

I didnt know if i was under some kind of pop3 connection attack or what. Im dreading having to tell my boss that we need to go back to courier pop3... UGH.

I was able to have a single P4 3ghz server be our pop3 server, now one quad core double the ram box running dovecot as the pop3 server is falling over, am I just doing something totally wrong here? /frustrated ramble ramble....