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@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 =
Xavier
-- xavier.pons@uib.es Centre de Tecnologies de la Informació Universitat Illes Balears