Hi,

I've just upgraded dovecot to 2.2.21 (from 2.2.18), and I'm getting a crash when doing dsync backup:

$ dsync -v -u user@domain.com backup maildir:/backup/maildirs/domain.com/user/Maildir dsync(user@domain.com): Panic: file stats-plugin.c: line 324 (stats_user_deinit): assertion failed: (stats_global_user == user) dsync(user@domain.com): Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0(+0x7e4b4) [0x7f543d3c74b4] -> /usr/lib64/dovecot/libdovecot.so.0(+0x7e529) [0x7f543d3c7529] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7f543d372300] -> /usr/lib64/dovecot/lib90_stats_plugin.so(+0x4116) [0x7f543c95a116] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mail_user_unref+0x35) [0x7f543d68efd5] -> /usr/bin/dsync shasta@toxcorp.com done [0x420f90] -> /usr/bin/dsync user@domain.com done [0x421edc] -> /usr/bin/dsync user@domain.com done [0x413a2f] -> /lib64/libc.so.6(__libc_start_main+0xf0) [0x7f543cd80870] -> /usr/bin/dsync user@domain.com done [0x413bb9] Aborted

This gets logged to syslog when it happens:

Dec 13 02:12:33 host dovecot: imap-login: Login: user=user@domain.com, method=PLAIN, rip=A.B.C.D, lip=A.B.C.D, mpid=1576, TLS Dec 13 02:13:09 host dovecot: stats: Error: Mail server input error: CONNECT: Duplicate session ID 4rqRBSXGbFbDBgAAOpfmEQ for user user@domain.com service doveadm

It definitely wasn't happening on 2.2.18 (I skipped .19 and .20).

Here's my configuration (with some things sanitized):

$ dovecot -n # 2.2.21 (5345f22): /etc/dovecot/dovecot.conf # Pigeonhole version 0.4.9 (357ac0a0e68b+) # OS: Linux 4.3.2 x86_64 Slackware 14.2 auth_cache_negative_ttl = 1 mins auth_cache_size = 4 k auth_mechanisms = plain login auth_socket_path = /var/run/dovecot/auth-userdb auth_verbose = yes auth_verbose_passwords = sha1 default_vsz_limit = 512 M deliver_log_format = msgid=%m psize=%p vsize=%w: %$ first_valid_gid = 500 first_valid_uid = 500 hostname = host.domain.com last_valid_gid = 500 last_valid_uid = 500 listen = * login_greeting = IMAP server ready. login_log_format_elements = user=<%u> method=%m rip=%r lip=%l mpid=%e %c mail_location = mdbox:~/mdbox:ALT=/var/vmail/altmdbox/%Ld/%Ln/altmdbox mail_plugins = " stats" mailbox_list_index = 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 index ihave duplicate namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Spam { special_use = \Junk } mailbox Trash { special_use = \Trash } prefix = separator = / type = private } passdb { args = scheme=CRYPT username_format=%Lu /etc/dovecot/users driver = passwd-file } plugin { mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename mail_log_fields = uid box msgid size recipient_delimiter = + sieve = ~/.dovecot.sieve sieve_default = /var/vmail/_sieve/default.sieve sieve_dir = ~/sieve stats_refresh = 30 secs stats_track_cmds = yes } pop3_client_workarounds = outlook-no-nuls postmaster_address = postmaster@domain.com protocols = imap pop3 lmtp sieve quota_full_tempfail = yes service auth-worker { user = $default_internal_user } service auth { unix_listener /var/spool/postfix/private/auth { group = postfix mode = 0660 user = postfix } } service dict { unix_listener dict { group = vmail mode = 0660 user = vmail } } service imap-login { inet_listener imap { port = 143 } inet_listener imaps { port = 993 ssl = yes } service_count = 1 } service imap { process_limit = 128 } service lmtp { inet_listener lmtp { address = 127.0.0.1 port = 2424 } unix_listener /var/spool/postfix/private/dovecot-lmtp { group = postfix mode = 0660 user = postfix } unix_listener lmtp-vmail { group = vmail mode = 0660 user = vmail } } service managesieve-login { inet_listener sieve { port = 4190 } service_count = 1 vsz_limit = 64 M } service managesieve { process_limit = 32 } service pop3-login { inet_listener pop3 { port = 110 } inet_listener pop3s { port = 995 ssl = yes } } service pop3 { process_limit = 64 } service stats { fifo_listener stats-mail { mode = 0600 user = vmail } } ssl_cert =

Let me know if there's anything else that I can provide to help narrowing it down.

Cheers, shasta

-- Jakub Jankowski|shasta@toxcorp.com|http://toxcorp.com/ GPG: FCBF F03D 9ADB B768 8B92 BB52 0341 9037 A875 942D