Pop3 service stops responding
Hi!
I have problem with the pop3 service stops responding at random intervals on my server. We started to notice this problem as we're running icinga to check the imap & pop3 service.
When icinga reports that the service is down. We try to telnet to the server on port 110 but it refuses the connection.
I've checked the netstat during this time and it's listens on port 110. My first thought we were hitting the max connections and similar.
Changed login_max_connections from 128 to 256. Didnt solve the problem.
Started the debug on the dovecot server but could not see anything in the logs. Also the error log or the syslog dosnt report anything that I can see.
Best thing would of course be to start and upgrade the software and os(Debian 5) but I'm not comfortable upgrading it at the moment as my knowledge about dovecot / postfix isn't great.
Do you have any idéas how to move forward?
dovecot -n # 1.0.15: /etc/dovecot/dovecot.conf base_dir: /var/run/dovecot/ log_path: /var/log/dovecot-error.log info_log_path: /var/log/dovecot-info.log log_timestamp: %Y-%m-%d %H:%M:%S protocols: pop3 imap imaps pop3s ssl_cipher_list: ALL:!LOW disable_plaintext_auth: no login_dir: /var/run/dovecot//login login_executable(default): /usr/lib/dovecot/imap-login login_executable(imap): /usr/lib/dovecot/imap-login login_executable(pop3): /usr/lib/dovecot/pop3-login login_max_processes_count: 256 first_valid_uid: 1090 last_valid_uid: 1090 first_valid_gid: 1090 last_valid_gid: 1090 mail_privileged_group: mail mail_location: maildir:~/Maildir mail_executable(default): /usr/lib/dovecot/imap mail_executable(imap): /usr/lib/dovecot/imap mail_executable(pop3): /usr/lib/dovecot/pop3 mail_plugins(default): quota imap_quota mail_plugins(imap): quota imap_quota mail_plugins(pop3): quota mail_plugin_dir(default): /usr/lib/dovecot/modules/imap mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3 pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %08Xu%08Xv auth default: username_chars: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@% username_translation: %@ username_format: %Lu passdb: driver: sql args: /etc/dovecot/dovecot-sql.conf userdb: driver: passwd userdb: driver: sql args: /etc/dovecot/dovecot-sql.conf socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/run/dovecot/auth-master mode: 384 user: vmail group: vmail plugin: quota: maildir sieve_global_path: /etc/dovecot/sieve_scripts/spam-sort.sieve
login_max_processes_count: 256 login_max_connections: 256 max_mail_processes: 1024
Best Regards Mike
Hello Mike,
Same thing here with one of our servers on the last week, but it only affected IMAP service and local connections.
The dovecot was not responding about 10% of attempted connections.
We could not find any hints in the logs, and the problem was unrelated to connections limit or dovecot configuration (we also tried the default setting).
Nothing solved the problem (service restart, default config, etc) only a server reboot.
CentOS 6.6 x64 Dovecot 2.2.18
*Victor Benincasa* CIO / CTO :: Networks, Apps, Systems, Security, High-end support
On 02/06/2015 04:35, Mike Eriksson wrote:
Hi!
I have problem with the pop3 service stops responding at random intervals on my server. We started to notice this problem as we're running icinga to check the imap & pop3 service.
When icinga reports that the service is down. We try to telnet to the server on port 110 but it refuses the connection.
I've checked the netstat during this time and it's listens on port 110. My first thought we were hitting the max connections and similar.
Changed login_max_connections from 128 to 256. Didnt solve the problem.
Started the debug on the dovecot server but could not see anything in the logs. Also the error log or the syslog dosnt report anything that I can see.
Best thing would of course be to start and upgrade the software and os(Debian 5) but I'm not comfortable upgrading it at the moment as my knowledge about dovecot / postfix isn't great.
Do you have any idéas how to move forward?
dovecot -n # 1.0.15: /etc/dovecot/dovecot.conf base_dir: /var/run/dovecot/ log_path: /var/log/dovecot-error.log info_log_path: /var/log/dovecot-info.log log_timestamp: %Y-%m-%d %H:%M:%S protocols: pop3 imap imaps pop3s ssl_cipher_list: ALL:!LOW disable_plaintext_auth: no login_dir: /var/run/dovecot//login login_executable(default): /usr/lib/dovecot/imap-login login_executable(imap): /usr/lib/dovecot/imap-login login_executable(pop3): /usr/lib/dovecot/pop3-login login_max_processes_count: 256 first_valid_uid: 1090 last_valid_uid: 1090 first_valid_gid: 1090 last_valid_gid: 1090 mail_privileged_group: mail mail_location: maildir:~/Maildir mail_executable(default): /usr/lib/dovecot/imap mail_executable(imap): /usr/lib/dovecot/imap mail_executable(pop3): /usr/lib/dovecot/pop3 mail_plugins(default): quota imap_quota mail_plugins(imap): quota imap_quota mail_plugins(pop3): quota mail_plugin_dir(default): /usr/lib/dovecot/modules/imap mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3 pop3_uidl_format(default): pop3_uidl_format(imap): pop3_uidl_format(pop3): %08Xu%08Xv auth default: username_chars: abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@% username_translation: %@ username_format: %Lu passdb: driver: sql args: /etc/dovecot/dovecot-sql.conf userdb: driver: passwd userdb: driver: sql args: /etc/dovecot/dovecot-sql.conf socket: type: listen client: path: /var/spool/postfix/private/auth mode: 432 user: postfix group: postfix master: path: /var/run/dovecot/auth-master mode: 384 user: vmail group: vmail plugin: quota: maildir sieve_global_path: /etc/dovecot/sieve_scripts/spam-sort.sieve
login_max_processes_count: 256 login_max_connections: 256 max_mail_processes: 1024
Best Regards Mike
participants (2)
-
Mike Eriksson
-
Victor Benincasa