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.p...@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.p...@uib.es
> Centre de Tecnologies de la Informació
> Universitat Illes Balears
>
>
