Hello,
I finally took time to isolate and reproduce a long time Dovecot crash that is bugging me since at least Dovecot 1.0.x. It's still there in Dovecot 2.0.9, which I just tested.
Here is the backtrace from my logs:
Feb 16 16:56:57 dovecot: auth: Error: pgsql: Query timed out, aborting Feb 16 17:25:16 dovecot: auth: Panic: file driver-pgsql.c: line 349 (result_finish): assertion failed: (db->io == NULL) Feb 16 17:25:16 dovecot: auth: Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0 [0x7fdbfe6d4272] -> /usr/lib/dovecot/libdovecot.so.0 [0x7fdbfe6d42d6] -> /usr/lib/dovecot/libdovecot.so.0(i_error+0) [0x7fdbfe6d46c8] -> dovecot/auth [0x42f555] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_handle_timeouts+0xdd) [0x7fdbfe6df9bd] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x5e) [0x7fdbfe6e05be] -> /usr/lib/dovecot/libdovecot.so.0(io_loop_run+0x28) [0x7fdbfe6df618] -> /usr/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7fdbfe6cd883] -> dovecot/auth(main+0x2d4) [0x419474] -> /lib/libc.so.6(__libc_start_main+0xe6) [0x7fdbfc4f91a6] -> dovecot/auth [0x40da09] Feb 16 17:26:35 dovecot: master: Error: service(auth): child 140263 killed with signal 6 (core not dumped)
Both my userdb and passdb use a PostgreSQL database. The bug happens when the PostgreSQL host suddenly becomes unavailable. I can easily reproduce it by launching Dovecot with my host being up, and then null routing its IP address (to simulate an outage):
route add -host 10.0.0.2 reject
(10.0.0.2 being the IP address of the PostgreSQL host.)
From that point, if I try to authenticate (using a POP3 connection, for instance), dovecot-auth will crash one or two minutes later.
In Dovecot 2.0.9, despite the crash, authentication will resume once the PostgreSQL is back up (which can be simulated with: route delete -host 10.0.0.2 reject). In Dovecot 1.x however (latest version I tested is 1.2.11), it will stay in this state forever (logs are flooded with Password query failed: Not connected to database.)
Core dump is available on http://paste.excellency.fr/dovecot.core
# dovecot -n
# 2.0.9: /etc/dovecot/dovecot.conf # OS: Linux 2.6.37 x86_64 Debian 5.0.6 auth_mechanisms = plain login auth_username_chars = disable_plaintext_auth = no first_valid_gid = 2000 first_valid_uid = 2000 listen = *, [::] log_timestamp = "%Y-%m-%d %H:%M:%S " mail_fsync = always mail_location = maildir:~/ mail_max_userip_connections = 100 mail_nfs_index = yes mail_nfs_storage = 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 mmap_disable = yes passdb { args = /etc/dovecot/dovecot-pgsql.conf driver = sql } plugin { quota = maildir sieve = filter.sieve sieve_max_actions = 64 sieve_max_redirects = 100 } protocols = imap pop3 service auth { unix_listener auth-client { mode = 0666 } } service imap-login { service_count = 0 } service imap { process_limit = 1024 } service managesieve-login { service_count = 0 } service pop3-login { service_count = 0 } service pop3 { process_limit = 1024 } ssl_cert =
# cat /etc/dovecot/dovecot-pgsql.conf
driver = pgsql connect = host=10.0.0.2 dbname=foobar user=dovecot password=foobar
default_pass_scheme = CRYPT
password_query = SELECT password FROM mailbox WHERE domain = '%d' AND local_part = '%n' user_query = SELECT home, uid, gid, system_user, quota_rule FROM mailbox WHERE domain = '%d' AND local_part = '%n'
-- Cyril