Hello, Am 29.05.2018 um 09:22 schrieb Aki Tuomi:> > On 29.05.2018 09:54, Hajo Locke wrote: >> Hello List, >> >> i use dovecot 2.2.22 and have the same problem described here: >> https://dovecot.org/pipermail/dovecot/2017-November/110020.html >> >> I can confirm that sometimes there is a problem with connection to >> mysql-db, but sometimes not. >> Reasons for failing are still under investigation by my mates. >> >> My current main problem is, that this fail seems to be a one way >> ticket for dovecot. Even if mysql is verifyable working again and >> waiting for connection dovecot stucks furthermore with errors like this: >> >> May 29 07:00:49 hostname dovecot: auth: Error: >> plain(mail at example.com,xxx.xxx.xx.xxx,<HGI4FVFt2Oy80j3P>): Request >> 999.7 timed out after 150 secs, state=1 >> >> When restarting dovecot all is immediately working again. >> Is there a way to tell dovecot to restart auth services or >> reinitialize mysql-connection after these hard fails? I could insert >> "idle_kill = 1 mins" into service auth and service auth-worker, but i >> dont know if this would work. Unfortunately i am not able to reproduce >> this error and there are always a couple of days between errors. >> >> Thanks, >> Hajo >> >> > Hi! > > I was not able to repeat this problem using 2.2.36. Can you provide > steps to reproduce? > > May 29 10:20:24 auth: Debug: client in: AUTH??? 1??? PLAIN > service=imap??? secured??? session=XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB > lip=::1??? rip=::1??? lport=143??? rport=58689??? resp=<hidden> > May 29 10:20:24 auth-worker(31098): Debug: > sql(test at domain.org,::1,<XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB>): query: > SELECT userid AS username, domain, password FROM users WHERE userid > 'test' AND domain = 'domain.org' > May 29 10:20:54 auth-worker(31098): Warning: mysql: Query failed, > retrying: Lost connection to MySQL server during query (idled for 28 secs) > May 29 10:20:59 auth-worker(31098): Error: mysql(127.0.0.1): Connect > failed to database (dovecot): Can't connect to MySQL server on > '127.0.0.1' (4) - waiting for 5 seconds before retry > May 29 10:21:04 auth-worker(31098): Error: mysql(127.0.0.1): Connect > failed to database (dovecot): Can't connect to MySQL server on > '127.0.0.1' (4) - waiting for 5 seconds before retry > May 29 10:21:14 auth: Debug: auth client connected (pid=31134) > May 29 10:21:14 imap-login: Warning: Growing pool 'imap login commands' > with: 1024 > May 29 10:21:14 auth-worker(31098): Error: mysql(127.0.0.1): Connect > failed to database (dovecot): Can't connect to MySQL server on > '127.0.0.1' (4) - waiting for 25 seconds before retry > > This is what it looks like for me and after restoring connectivity, it > started working normally.Unfortunately i can not reproduce. Servers running well for days or sometimes weeks and then it happens one time. I can provide some more logs. This is an error with mysql involvement: May 29 06:56:59 hostname dovecot: auth-worker(1099): Error: mysql(xx.xx.xx.xx): Connect failed to database (mysql): Can't connect to MySQL server on 'xx.xx.xx.xx' (111) - waiting for 1 seconds before retry . . some more of above line . May 29 06:56:59 hostname dovecot: auth-worker(1110): Error: sql(mail at example.com,xx.xx.xx.xx): Password query failed: Not connected to database May 29 06:56:59 hostname dovecot: auth: Error: auth worker: Aborted PASSV request for mail at example.com: Internal auth worker failure May 29 06:57:59 hostname dovecot: auth-worker(1099): Error: mysql: Query timed out (no free connections for 60 secs): SELECT `inbox` as `user`, `password` FROM `mail_users` WHERE `login` = 'username' AND `active`='Y' May 29 06:59:30 hostname dovecot: auth: Error: plain(username,xx.xx.xx.xx,<jc9yEFFtXcJXmx0F>): Request 999.2 timed out after 151 secs, state=1 . . much more of these lines with Request timed out . At this point my mates restartet dovecot and all worked well immediately. Mysql performed a short restart at 6:56 and dovecot was not able to reconnect for about 10 mins until my mates did the restart. I could not reproduce the problem by manually restarting of mysql, this worked well. This is an error without visible mysql involvement: . . lines of normal imap/pop activity . May 29 05:43:03 hostname dovecot: imap-login: Error: master(imap): Auth request timed out (received 0/12 bytes) May 29 05:43:03 hostname dovecot: imap-login: Internal login failure (pid=1014 id=16814) (internal failure, 1 successful auths): user=<username>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS May 29 05:43:03 hostname dovecot: imap: Error: Login client disconnected too early May 29 05:44:03 hostname dovecot: auth: Error: plain(username,xx.xx.xx.xx,<Wry1AlBt7couU7FV>): Request 1014.16815 timed out after 150 secs, state=1 May 29 05:44:08 hostname dovecot: imap: Error: Auth server request timed out after 155 secs (client-pid=1014 client-id=16814) May 29 05:44:33 hostname dovecot: imap-login: Disconnected: Inactivity during authentication (disconnected while authenticating, waited 180 secs): user=<>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS: Disconnected May 29 05:46:07 hostname dovecot: auth: Error: plain(mail at example.com,xx.xx.xx.xx,<j2cWClBtVf3Z+t+p>): Request 1014.16819 timed out after 150 secs, state=1 . . and so on until restart . There is no errorlog in relation to mysql written by dovecot. We use 2.2.22 because this version is provided with Ubuntu 16.04 and Ubuntu Team is maintaining software and providing security patches, which happens 2017 and 2018 a couple of times. By manually compiling and using newer versions you have to check updates by yourself and you are forced to run every single update. Our goal is reliability which contradicts to use of bleeding edge software. This is output of current doveconf -n # 2.2.22 (fe789d2): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.13 (7b14904) # OS: Linux 4.4.0-127-generic x86_64 Ubuntu 16.04.4 LTS auth_mechanisms = plain login auth_username_chars = abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@?????? auth_worker_max_count = 60 disable_plaintext_auth = no imap_capability = +XLIST lock_method = flock login_greeting = mailserver ready. login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c mail_cache_min_mail_count = 30 mail_location = mbox:~/mail:INBOX=/var/mail/%u mail_max_userip_connections = 30 mbox_read_locks = dotlock mbox_very_dirty_syncs = yes namespace inbox { ? inbox = yes ? location ? mailbox Archiv { ??? auto = no ??? special_use ? } ? mailbox Drafts { ??? auto = no ??? special_use ? } ? mailbox Junk { ??? auto = no ??? special_use ? } ? mailbox Sent { ??? auto = no ??? special_use ? } ? mailbox Trash { ??? auto = no ??? special_use ? } ? prefix } passdb { ? args = /etc/dovecot/dovecot-sql.conf ? driver = sql } protocols = imap pop3 service auth { ? unix_listener /var/spool/postfix/private/auth { ??? group = postfix ??? mode = 0660 ??? user = postfix ? } ? user = root } service imap-login { ? executable = /usr/lib/dovecot/imap-login ? process_min_avail = 1 ? service_count = 0 ? user = dovecot } service imap { ? process_limit = 1024 } service pop3-login { ? executable = /usr/lib/dovecot/pop3-login ? process_min_avail = 1 ? service_count = 0 ? user = dovecot } service pop3 { ? executable = /usr/lib/dovecot/pop3 ? process_limit = 1024 } shutdown_clients = no ssl_ca = </path/path/cert.pem ssl_cert = </path/path/cert.pem ssl_cipher_list = ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:!DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA ssl_dh_parameters_length = 2048 ssl_key = </path/path/cert.pem ssl_prefer_server_ciphers = yes ssl_protocols = !SSLv2 !SSLv3 userdb { ? args = /etc/dovecot/dovecot-sql.conf ? driver = sql } verbose_proctitle = yes protocol imap { ? imap_client_workarounds = delay-newmail ? mail_plugins = mail_log notify ? ssl = yes } protocol pop3 { ? pop3_client_workarounds = oe-ns-eoh outlook-no-nuls ? pop3_no_flag_updates = no ? pop3_uidl_format = %08Xu%08Xv ? ssl = yes } I hope you have some hints. I dislike to monitor this with fail2ban and do hard restarts.> Aki >Thanks, Hajo
On 29.05.2018 11:35, Hajo Locke wrote:> Hello, > > > Am 29.05.2018 um 09:22 schrieb Aki Tuomi: >> >> On 29.05.2018 09:54, Hajo Locke wrote: >>> Hello List, >>> >>> i use dovecot 2.2.22 and have the same problem described here: >>> https://dovecot.org/pipermail/dovecot/2017-November/110020.html >>> >>> I can confirm that sometimes there is a problem with connection to >>> mysql-db, but sometimes not. >>> Reasons for failing are still under investigation by my mates. >>> >>> My current main problem is, that this fail seems to be a one way >>> ticket for dovecot. Even if mysql is verifyable working again and >>> waiting for connection dovecot stucks furthermore with errors like >>> this: >>> >>> May 29 07:00:49 hostname dovecot: auth: Error: >>> plain(mail at example.com,xxx.xxx.xx.xxx,<HGI4FVFt2Oy80j3P>): Request >>> 999.7 timed out after 150 secs, state=1 >>> >>> When restarting dovecot all is immediately working again. >>> Is there a way to tell dovecot to restart auth services or >>> reinitialize mysql-connection after these hard fails? I could insert >>> "idle_kill = 1 mins" into service auth and service auth-worker, but i >>> dont know if this would work. Unfortunately i am not able to reproduce >>> this error and there are always a couple of days between errors. >>> >>> Thanks, >>> Hajo >>> >>> >> Hi! >> >> I was not able to repeat this problem using 2.2.36. Can you provide >> steps to reproduce? >> >> May 29 10:20:24 auth: Debug: client in: AUTH??? 1??? PLAIN >> service=imap??? secured??? session=XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB >> lip=::1??? rip=::1??? lport=143??? rport=58689??? resp=<hidden> >> May 29 10:20:24 auth-worker(31098): Debug: >> sql(test at domain.org,::1,<XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB>): query: >> SELECT userid AS username, domain, password FROM users WHERE userid >> 'test' AND domain = 'domain.org' >> May 29 10:20:54 auth-worker(31098): Warning: mysql: Query failed, >> retrying: Lost connection to MySQL server during query (idled for 28 >> secs) >> May 29 10:20:59 auth-worker(31098): Error: mysql(127.0.0.1): Connect >> failed to database (dovecot): Can't connect to MySQL server on >> '127.0.0.1' (4) - waiting for 5 seconds before retry >> May 29 10:21:04 auth-worker(31098): Error: mysql(127.0.0.1): Connect >> failed to database (dovecot): Can't connect to MySQL server on >> '127.0.0.1' (4) - waiting for 5 seconds before retry >> May 29 10:21:14 auth: Debug: auth client connected (pid=31134) >> May 29 10:21:14 imap-login: Warning: Growing pool 'imap login commands' >> with: 1024 >> May 29 10:21:14 auth-worker(31098): Error: mysql(127.0.0.1): Connect >> failed to database (dovecot): Can't connect to MySQL server on >> '127.0.0.1' (4) - waiting for 25 seconds before retry >> >> This is what it looks like for me and after restoring connectivity, it >> started working normally. > Unfortunately i can not reproduce. Servers running well for days or > sometimes weeks and then it happens one time. I can provide some more > logs. > > This is an error with mysql involvement: > > May 29 06:56:59 hostname dovecot: auth-worker(1099): Error: > mysql(xx.xx.xx.xx): Connect failed to database (mysql): Can't connect > to MySQL server on 'xx.xx.xx.xx' (111) - waiting for 1 seconds before > retry > . > . some more of above line > . > May 29 06:56:59 hostname dovecot: auth-worker(1110): Error: > sql(mail at example.com,xx.xx.xx.xx): Password query failed: Not > connected to database > May 29 06:56:59 hostname dovecot: auth: Error: auth worker: Aborted > PASSV request for mail at example.com: Internal auth worker failure > May 29 06:57:59 hostname dovecot: auth-worker(1099): Error: mysql: > Query timed out (no free connections for 60 secs): SELECT `inbox` as > `user`, `password` FROM `mail_users` WHERE `login` = 'username' AND > `active`='Y' > May 29 06:59:30 hostname dovecot: auth: Error: > plain(username,xx.xx.xx.xx,<jc9yEFFtXcJXmx0F>): Request 999.2 timed > out after 151 secs, state=1 > . > . much more of these lines with Request timed out > . > > At this point my mates restartet dovecot and all worked well > immediately. Mysql performed a short restart at 6:56 and dovecot was > not able to reconnect for about 10 mins until my mates did the > restart. I could not reproduce the problem by manually restarting of > mysql, this worked well. > > This is an error without visible mysql involvement: > . > . lines of normal imap/pop activity > . > May 29 05:43:03 hostname dovecot: imap-login: Error: master(imap): > Auth request timed out (received 0/12 bytes) > May 29 05:43:03 hostname dovecot: imap-login: Internal login failure > (pid=1014 id=16814) (internal failure, 1 successful auths): > user=<username>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS > May 29 05:43:03 hostname dovecot: imap: Error: Login client > disconnected too early > May 29 05:44:03 hostname dovecot: auth: Error: > plain(username,xx.xx.xx.xx,<Wry1AlBt7couU7FV>): Request 1014.16815 > timed out after 150 secs, state=1 > May 29 05:44:08 hostname dovecot: imap: Error: Auth server request > timed out after 155 secs (client-pid=1014 client-id=16814) > May 29 05:44:33 hostname dovecot: imap-login: Disconnected: Inactivity > during authentication (disconnected while authenticating, waited 180 > secs): user=<>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS: > Disconnected > May 29 05:46:07 hostname dovecot: auth: Error: > plain(mail at example.com,xx.xx.xx.xx,<j2cWClBtVf3Z+t+p>): Request > 1014.16819 timed out after 150 secs, state=1 > . > . and so on until restart > . > > There is no errorlog in relation to mysql written by dovecot. > > We use 2.2.22 because this version is provided with Ubuntu 16.04 and > Ubuntu Team is maintaining software and providing security patches, > which happens 2017 and 2018 a couple of times. By manually compiling > and using newer versions you have to check updates by yourself and you > are forced to run every single update. Our goal is reliability which > contradicts to use of bleeding edge software. > > > This is output of current doveconf -n > > # 2.2.22 (fe789d2): /etc/dovecot/dovecot.conf > # Pigeonhole version 0.4.13 (7b14904) > # OS: Linux 4.4.0-127-generic x86_64 Ubuntu 16.04.4 LTS > auth_mechanisms = plain login > auth_username_chars > abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@?????? > auth_worker_max_count = 60 > disable_plaintext_auth = no > imap_capability = +XLIST > lock_method = flock > login_greeting = mailserver ready. > login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c > mail_cache_min_mail_count = 30 > mail_location = mbox:~/mail:INBOX=/var/mail/%u > mail_max_userip_connections = 30 > mbox_read_locks = dotlock > mbox_very_dirty_syncs = yes > namespace inbox { > ? inbox = yes > ? location > ? mailbox Archiv { > ??? auto = no > ??? special_use > ? } > ? mailbox Drafts { > ??? auto = no > ??? special_use > ? } > ? mailbox Junk { > ??? auto = no > ??? special_use > ? } > ? mailbox Sent { > ??? auto = no > ??? special_use > ? } > ? mailbox Trash { > ??? auto = no > ??? special_use > ? } > ? prefix > } > passdb { > ? args = /etc/dovecot/dovecot-sql.conf > ? driver = sql > } > protocols = imap pop3 > service auth { > ? unix_listener /var/spool/postfix/private/auth { > ??? group = postfix > ??? mode = 0660 > ??? user = postfix > ? } > ? user = root > } > service imap-login { > ? executable = /usr/lib/dovecot/imap-login > ? process_min_avail = 1 > ? service_count = 0 > ? user = dovecot > } > service imap { > ? process_limit = 1024 > } > service pop3-login { > ? executable = /usr/lib/dovecot/pop3-login > ? process_min_avail = 1 > ? service_count = 0 > ? user = dovecot > } > service pop3 { > ? executable = /usr/lib/dovecot/pop3 > ? process_limit = 1024 > } > shutdown_clients = no > ssl_ca = </path/path/cert.pem > ssl_cert = </path/path/cert.pem > ssl_cipher_list > ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:!DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA > ssl_dh_parameters_length = 2048 > ssl_key = </path/path/cert.pem > ssl_prefer_server_ciphers = yes > ssl_protocols = !SSLv2 !SSLv3 > userdb { > ? args = /etc/dovecot/dovecot-sql.conf > ? driver = sql > } > verbose_proctitle = yes > protocol imap { > ? imap_client_workarounds = delay-newmail > ? mail_plugins = mail_log notify > ? ssl = yes > } > protocol pop3 { > ? pop3_client_workarounds = oe-ns-eoh outlook-no-nuls > ? pop3_no_flag_updates = no > ? pop3_uidl_format = %08Xu%08Xv > ? ssl = yes > } > > I hope you have some hints. I dislike to monitor this with fail2ban > and do hard restarts. >> Aki >> > > Thanks, > HajoCan you try doing successful auth MySQL, then, for short while, blocking access to MySQL server using iptables (no idea how to do this with socket based), and try authenticating while access is blocked. It should, hopefully, reproduce this error. The critical bits are that you MUST login successfully once (so that auth-worker is started and connects to SQL database), you must block the access using iptables -j DROP (to make sure the connection "goes away"), and wait long enough for mysql driver to realize this too, it might take few seconds. Aki
> Am 29.05.2018 um 11:00 schrieb Aki Tuomi <aki.tuomi at dovecot.fi>: > > > > On 29.05.2018 11:35, Hajo Locke wrote: >> Hello, >> >> >> Am 29.05.2018 um 09:22 schrieb Aki Tuomi: >>> >>> On 29.05.2018 09:54, Hajo Locke wrote: >>>> Hello List, >>>> >>>> i use dovecot 2.2.22 and have the same problem described here: >>>> https://dovecot.org/pipermail/dovecot/2017-November/110020.html >>>> >>>> I can confirm that sometimes there is a problem with connection to >>>> mysql-db, but sometimes not. >>>> Reasons for failing are still under investigation by my mates. >>>> >>>> My current main problem is, that this fail seems to be a one way >>>> ticket for dovecot. Even if mysql is verifyable working again and >>>> waiting for connection dovecot stucks furthermore with errors like >>>> this: >>>> >>>> May 29 07:00:49 hostname dovecot: auth: Error: >>>> plain(mail at example.com,xxx.xxx.xx.xxx,<HGI4FVFt2Oy80j3P>): Request >>>> 999.7 timed out after 150 secs, state=1 >>>> >>>> When restarting dovecot all is immediately working again. >>>> Is there a way to tell dovecot to restart auth services or >>>> reinitialize mysql-connection after these hard fails? I could insert >>>> "idle_kill = 1 mins" into service auth and service auth-worker, but i >>>> dont know if this would work. Unfortunately i am not able to reproduce >>>> this error and there are always a couple of days between errors. >>>> >>>> Thanks, >>>> Hajo >>>> >>>> >>> Hi! >>> >>> I was not able to repeat this problem using 2.2.36. Can you provide >>> steps to reproduce? >>> >>> May 29 10:20:24 auth: Debug: client in: AUTH 1 PLAIN >>> service=imap secured session=XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB >>> lip=::1 rip=::1 lport=143 rport=58689 resp=<hidden> >>> May 29 10:20:24 auth-worker(31098): Debug: >>> sql(test at domain.org,::1,<XtpgEVNtQeUAAAAAAAAAAAAAAAAAAAAB>): query: >>> SELECT userid AS username, domain, password FROM users WHERE userid >>> 'test' AND domain = 'domain.org' >>> May 29 10:20:54 auth-worker(31098): Warning: mysql: Query failed, >>> retrying: Lost connection to MySQL server during query (idled for 28 >>> secs) >>> May 29 10:20:59 auth-worker(31098): Error: mysql(127.0.0.1): Connect >>> failed to database (dovecot): Can't connect to MySQL server on >>> '127.0.0.1' (4) - waiting for 5 seconds before retry >>> May 29 10:21:04 auth-worker(31098): Error: mysql(127.0.0.1): Connect >>> failed to database (dovecot): Can't connect to MySQL server on >>> '127.0.0.1' (4) - waiting for 5 seconds before retry >>> May 29 10:21:14 auth: Debug: auth client connected (pid=31134) >>> May 29 10:21:14 imap-login: Warning: Growing pool 'imap login commands' >>> with: 1024 >>> May 29 10:21:14 auth-worker(31098): Error: mysql(127.0.0.1): Connect >>> failed to database (dovecot): Can't connect to MySQL server on >>> '127.0.0.1' (4) - waiting for 25 seconds before retry >>> >>> This is what it looks like for me and after restoring connectivity, it >>> started working normally. >> Unfortunately i can not reproduce. Servers running well for days or >> sometimes weeks and then it happens one time. I can provide some more >> logs. >> >> This is an error with mysql involvement: >> >> May 29 06:56:59 hostname dovecot: auth-worker(1099): Error: >> mysql(xx.xx.xx.xx): Connect failed to database (mysql): Can't connect >> to MySQL server on 'xx.xx.xx.xx' (111) - waiting for 1 seconds before >> retry >> . >> . some more of above line >> . >> May 29 06:56:59 hostname dovecot: auth-worker(1110): Error: >> sql(mail at example.com,xx.xx.xx.xx): Password query failed: Not >> connected to database >> May 29 06:56:59 hostname dovecot: auth: Error: auth worker: Aborted >> PASSV request for mail at example.com: Internal auth worker failure >> May 29 06:57:59 hostname dovecot: auth-worker(1099): Error: mysql: >> Query timed out (no free connections for 60 secs): SELECT `inbox` as >> `user`, `password` FROM `mail_users` WHERE `login` = 'username' AND >> `active`='Y' >> May 29 06:59:30 hostname dovecot: auth: Error: >> plain(username,xx.xx.xx.xx,<jc9yEFFtXcJXmx0F>): Request 999.2 timed >> out after 151 secs, state=1 >> . >> . much more of these lines with Request timed out >> . >> >> At this point my mates restartet dovecot and all worked well >> immediately. Mysql performed a short restart at 6:56 and dovecot was >> not able to reconnect for about 10 mins until my mates did the >> restart. I could not reproduce the problem by manually restarting of >> mysql, this worked well. >> >> This is an error without visible mysql involvement: >> . >> . lines of normal imap/pop activity >> . >> May 29 05:43:03 hostname dovecot: imap-login: Error: master(imap): >> Auth request timed out (received 0/12 bytes) >> May 29 05:43:03 hostname dovecot: imap-login: Internal login failure >> (pid=1014 id=16814) (internal failure, 1 successful auths): >> user=<username>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS >> May 29 05:43:03 hostname dovecot: imap: Error: Login client >> disconnected too early >> May 29 05:44:03 hostname dovecot: auth: Error: >> plain(username,xx.xx.xx.xx,<Wry1AlBt7couU7FV>): Request 1014.16815 >> timed out after 150 secs, state=1 >> May 29 05:44:08 hostname dovecot: imap: Error: Auth server request >> timed out after 155 secs (client-pid=1014 client-id=16814) >> May 29 05:44:33 hostname dovecot: imap-login: Disconnected: Inactivity >> during authentication (disconnected while authenticating, waited 180 >> secs): user=<>, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS: >> Disconnected >> May 29 05:46:07 hostname dovecot: auth: Error: >> plain(mail at example.com,xx.xx.xx.xx,<j2cWClBtVf3Z+t+p>): Request >> 1014.16819 timed out after 150 secs, state=1 >> . >> . and so on until restart >> . >> >> There is no errorlog in relation to mysql written by dovecot. >> >> We use 2.2.22 because this version is provided with Ubuntu 16.04 and >> Ubuntu Team is maintaining software and providing security patches, >> which happens 2017 and 2018 a couple of times. By manually compiling >> and using newer versions you have to check updates by yourself and you >> are forced to run every single update. Our goal is reliability which >> contradicts to use of bleeding edge software. >> >> >> This is output of current doveconf -n >> >> # 2.2.22 (fe789d2): /etc/dovecot/dovecot.conf >> # Pigeonhole version 0.4.13 (7b14904) >> # OS: Linux 4.4.0-127-generic x86_64 Ubuntu 16.04.4 LTS >> auth_mechanisms = plain login >> auth_username_chars >> abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890.-_@?????? >> auth_worker_max_count = 60 >> disable_plaintext_auth = no >> imap_capability = +XLIST >> lock_method = flock >> login_greeting = mailserver ready. >> login_log_format_elements = user=<%u> method=%m rip=%r lip=%l %c >> mail_cache_min_mail_count = 30 >> mail_location = mbox:~/mail:INBOX=/var/mail/%u >> mail_max_userip_connections = 30 >> mbox_read_locks = dotlock >> mbox_very_dirty_syncs = yes >> namespace inbox { >> inbox = yes >> location >> mailbox Archiv { >> auto = no >> special_use >> } >> mailbox Drafts { >> auto = no >> special_use >> } >> mailbox Junk { >> auto = no >> special_use >> } >> mailbox Sent { >> auto = no >> special_use >> } >> mailbox Trash { >> auto = no >> special_use >> } >> prefix >> } >> passdb { >> args = /etc/dovecot/dovecot-sql.conf >> driver = sql >> } >> protocols = imap pop3 >> service auth { >> unix_listener /var/spool/postfix/private/auth { >> group = postfix >> mode = 0660 >> user = postfix >> } >> user = root >> } >> service imap-login { >> executable = /usr/lib/dovecot/imap-login >> process_min_avail = 1 >> service_count = 0 >> user = dovecot >> } >> service imap { >> process_limit = 1024 >> } >> service pop3-login { >> executable = /usr/lib/dovecot/pop3-login >> process_min_avail = 1 >> service_count = 0 >> user = dovecot >> } >> service pop3 { >> executable = /usr/lib/dovecot/pop3 >> process_limit = 1024 >> } >> shutdown_clients = no >> ssl_ca = </path/path/cert.pem >> ssl_cert = </path/path/cert.pem >> ssl_cipher_list >> ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:!DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA >> ssl_dh_parameters_length = 2048 >> ssl_key = </path/path/cert.pem >> ssl_prefer_server_ciphers = yes >> ssl_protocols = !SSLv2 !SSLv3 >> userdb { >> args = /etc/dovecot/dovecot-sql.conf >> driver = sql >> } >> verbose_proctitle = yes >> protocol imap { >> imap_client_workarounds = delay-newmail >> mail_plugins = mail_log notify >> ssl = yes >> } >> protocol pop3 { >> pop3_client_workarounds = oe-ns-eoh outlook-no-nuls >> pop3_no_flag_updates = no >> pop3_uidl_format = %08Xu%08Xv >> ssl = yes >> } >> >> I hope you have some hints. I dislike to monitor this with fail2ban >> and do hard restarts. >>> Aki >>> >> >> Thanks, >> Hajo > > Can you try doing successful auth MySQL, then, for short while, blocking > access to MySQL server using iptables (no idea how to do this with > socket based), and try authenticating while access is blocked. It > should, hopefully, reproduce this error.You could try to remove the socket file when mysql is running and then using socat: socat UNIX-LISTEN:/var/lib/mysql/mysql.sock,fork,reuseaddr,unlink-early,mode=777 TCP:127.0.0.1:3306 Best regards Gerald