[Dovecot] lmtp panic in proxy lmtp director

[Dovecot-GDH]

This happens when the LMTP proxy doesn't receive feedback from the back-end LMTP process for a certain amount of time.

This typically happens either because of very low I/O performance or NFS locks. Do an strace on your back-end LMTP processes. If you see that these processes are waiting on NFS locks ande you are using NFSv3, you should move over to NFSv4.


On Dec 5, 2011, at 6:26 AM, Xavier Pons wrote:

> Hi, we are getting some  core dumps with signal 6 in ltmp on a dovecot director proxy server,
> like this:
> 
> Dec  5 14:31:51 sproxy1 dovecot: lmtp(29999): Panic: file lmtp-proxy.c: line 376 (lmtp_proxy_output_timeout): assertion failed: (proxy->data_input->eof)
> Dec  5 14:31:51 sproxy1 dovecot: lmtp(29999): Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0() [0x363323d99a] -> /usr/lib64/dovecot/libdovecot.so.0() [0x363323d9e6] -> /usr/lib64/dovecot/libdovecot.so.0(i_error+0) [0x3633216f8f] -> dovecot/lmtp() [0x406e57] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handle_timeouts+0xd4) [0x3633248ff4] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_handler_run+0x5b) [0x3633249bdb] -> /usr/lib64/dovecot/libdovecot.so.0(io_loop_run+0x28) [0x3633248c58] -> /usr/lib64/dovecot/libdovecot.so.0(master_service_run+0x13) [0x3633236fc3] -> dovecot/lmtp(main+0x154) [0x403f84] -> /lib64/libc.so.6(__libc_start_main+0xfd) [0x373cc1ec5d] -> dovecot/lmtp() [0x403d69]
> Dec  5 14:31:51 sproxy1 abrt[30067]: saved core dump of pid 29999 (/usr/libexec/dovecot/lmtp) to /var/spool/abrt/ccpp-1323091911-29999.new/coredump (1368064 bytes)
> Dec  5 14:31:51 sproxy1 dovecot: master: Error: service(lmtp): child 29999 killed with signal 6 (core dumped)
> 
> we have something misconfigured  or it's a bug on this dovecot version?
> 
> our doveconf -n is:
> # 2.0.15: /etc/dovecot/dovecot.conf
> # OS: Linux 2.6.32-71.29.1.el6.x86_64 x86_64 CentOS Linux release 6.0 (Final)
> auth_cache_size = 3 k
> auth_cache_ttl = 15 mins
> auth_verbose = yes
> base_dir = /var/run/dovecot/
> default_client_limit = 30000
> default_process_limit = 5000
> director_doveadm_port = 990
> director_mail_servers = 10.80.82.21 10.80.82.22
> director_servers = 10.80.82.11 10.80.82.12
> doveadm_proxy_port = 24245
> lmtp_proxy = yes
> managesieve_notify_capability = mailto
> managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave
> passdb {
>  args = proxy=y nopassword=y starttls=any-cert
>  driver = static
> }
> postmaster_address = xavier.pons at uib.es
> protocols = imap pop3 lmtp sieve
> service auth {
>  client_limit = 27048
>  unix_listener /var/spool/postfix/private/auth {
>    mode = 0666
>  }
>  unix_listener auth-userdb {
>    group = dovecot
>    mode = 0660
>  }
> }
> service director {
>  fifo_listener login/proxy-notify {
>    mode = 0666
>  }
>  inet_listener {
>    port = 991
>  }
>  inet_listener director-doveadm {
>    port = 990
>  }
>  unix_listener director-userdb {
>    mode = 0660
>  }
>  unix_listener login/director {
>    mode = 0666
>  }
> }
> service doveadm {
>  inet_listener {
>    port = 24245
>  }
> }
> service imap-login {
>  executable = imap-login director
>  inet_listener imap {
>    port = 143
>  }
>  inet_listener imaps {
>    port = 993
>    ssl = yes
>  }
> }
> service lmtp {
>  inet_listener lmtp {
>    port = 30025
>  }
> }
> service managesieve-login {
>  executable = managesieve-login director
> }
> service pop3-login {
>  executable = pop3-login director
>  inet_listener pop3 {
>    port = 110
>  }
>  inet_listener pop3s {
>    port = 995
>    ssl = yes
>  }
> }
> ssl = required
> ssl_cert = </etc/pki/tls/certs/imap.crt
> ssl_key = </etc/pki/tls/private/imap.uib.es_privatekey.pem
> syslog_facility = local1
> verbose_proctitle = yes
> protocol lmtp {
>  auth_socket_path = director-userdb
>  passdb {
>    args = /etc/dovecot/dovecot-ldap-pass.conf.lmtp
>    driver = ldap
>  }
> }
> protocol doveadm {
>  auth_socket_path = director-userdb
> }
> protocol imap {
>  mail_max_userip_connections = 20
> }
> protocol pop3 {
>  pop3_client_workarounds = outlook-no-nuls oe-ns-eoh
> }
> 
> Xavier
> 
> -- 
> xavier.pons at uib.es
> Centre de Tecnologies de la Informació
> Universitat Illes Balears
> 
>