Hi,

Here is a crash that's happening using the latest Dovecot version (v2.2.27 on CentOS7 x86_64):

We are using replication. Judging by the second server's logs, I believe this has something to do with the fact that we're using the lazy_expunge plugin.

Every night after midnight, we purge the lazy_expunge namespace by running a command similar to following one on the main server (server01 in the logs below): # doveadm expunge -A MAILBOX 'EXPUNGED/*' SAVEDBEFORE "$(date +'%F')"

The lazy_expunge namespace is configured as follows:

namespace expunged { disabled = no hidden = yes ignore_on_failure = no inbox = no list = no location = sdbox:/srv/mail/expunged/%1n/%n:SUBSCRIPTIONS=subscriptions-expunged order = 0 prefix = EXPUNGED/ separator = / subscriptions = no type = private }

plugin { lazy_expunge = EXPUNGED/ }

First server's logs:

2016-12-06T13:09:31.212620+01:00 server01 dovecot: dsync-server(user01): Panic: file dsync-mailbox-tree-sync.c: line 576 (node_mailbox_trees_cmp): assertion failed: (ret != 0) 2016-12-06T13:09:31.213473+01:00 server01 dovecot: dsync-server(user01): Error: Raw backtrace: /usr/local/lib/dovecot/libdovecot.so.0(+0x92d70) [0x7f57cc18ad70] -> /usr/local/lib/dovecot/libdovecot.so.0(+0x92e4e) [0x7f57cc18ae4e] -> /usr/local/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f57cc1264e0] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x447584] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x447a57] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x447849] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x447849] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x447cc9] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x43a477] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x436e4e] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x437280] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x44c5af] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x52) [0x7f57cc19e4d2] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0xe7) [0x7f57cc19fa07] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x3c) [0x7f57cc19e56c] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f57cc19e728] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x41faae] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x421316] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x433b64] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x52) [0x7f57cc19e4d2] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0xe7) [0x7f57cc19fa07] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x3c) [0x7f57cc19e56c] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f57cc19e728] -> /usr/local/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f57cc12c513] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x413b57] -> /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f57cbd57b15] -> dovecot/doveadm-server 10.0.0.2 user01 recv_mailbox_tree_deletes [0x413bf5] 2016-12-06T13:09:31.214076+01:00 server01 dovecot: dsync-server(user01): Fatal: master: service(doveadm): child 6837 killed with signal 6 (core dumps disabled) 2016-12-06T13:11:42.880516+01:00 server01 dovecot: dsync-local(user01): Error: read(server02.localdomain) failed: EOF (last sent=mailbox_delete, last recv=mailbox_tree_node)

Second server's logs:

2016-12-06T12:09:36.220591+01:00 server02 dovecot: doveadm(user01): Error: Duplicate mailbox GUID eab35824e49b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/Demissions C2i and EXPUNGED/Trash/C2i - Coordination/Demissions C2i - giving a new GUID c4ffaf08709c465813ae0000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/Demissions C2i 2016-12-06T12:09:36.220859+01:00 server02 dovecot: doveadm(user01): Error: Duplicate mailbox GUID 2ab10a2bee9b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2014-2015 and EXPUNGED/Trash/C2i - Coordination/2014-2015 - giving a new GUID c6ffaf08709c465813ae0000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2014-2015 2016-12-06T12:09:36.221091+01:00 server02 dovecot: doveadm(user01): Error: Duplicate mailbox GUID eeb35824e49b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2012-2013 and EXPUNGED/Trash/C2i - Coordination/2012-2013 - giving a new GUID c8ffaf08709c465813ae0000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2012-2013 2016-12-06T12:09:36.284224+01:00 server02 dovecot: dsync-local(user01): Error: Mailbox EXPUNGED/Trash/C2i - Coordination/2008-2009/Formation FC sync: mailbox_rename failed: Can't rename mailboxes to/from expunge namespace. 2016-12-06T12:09:45.469706+01:00 server02 dovecot: dsync-server(user01): Error: Duplicate mailbox GUID eab35824e49b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/Demissions C2i and EXPUNGED/Trash/C2i - Coordination/Demissions C2i - giving a new GUID 671ae30f799c465882b00000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/Demissions C2i 2016-12-06T12:09:45.470389+01:00 server02 dovecot: dsync-server(user01): Error: Duplicate mailbox GUID 2ab10a2bee9b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2014-2015 and EXPUNGED/Trash/C2i - Coordination/2014-2015 - giving a new GUID 691ae30f799c465882b00000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2014-2015 2016-12-06T12:09:45.471214+01:00 server02 dovecot: dsync-server(user01): Error: Duplicate mailbox GUID eeb35824e49b4658840001001776124f for mailboxes EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2012-2013 and EXPUNGED/Trash/C2i - Coordination/2012-2013 - giving a new GUID 6b1ae30f799c465882b00000a26dfa6e to EXPUNGED/Trash/C2i - Coordination-temp-ac1fea3af7e1f2c29ce1c62442a06272/2012-2013 2016-12-06T12:09:45.485663+01:00 server02 dovecot: dsync-server(user01): Error: Mailbox EXPUNGED/Trash/C2i - Coordination/2008-2009/Formation FC sync: mailbox_rename failed: Can't rename mailboxes to/from expunge namespace.

[... Previous line repeated numerous times ...]

2016-12-06T12:14:32.583382+01:00 server02 dovecot: dsync-server(user01): Error: Mailbox EXPUNGED/Trash/C2i - Coordination/2008-2009/Formation FC sync: mailbox_rename failed: Can't rename mailboxes to/from expunge namespace. 2016-12-06T12:14:36.778278+01:00 server02 dovecot: dsync-local(user01): Error: Mailbox EXPUNGED/Trash/C2i - Coordination/2008-2009/Formation FC sync: mailbox_rename failed: Can't rename mailboxes to/from expunge namespace.

[... / ...]

2016-12-06T12:19:30.677497+01:00 sauto dovecot: dsync-server(user01): Panic: file dsync-mailbox-tree-sync.c: line 576 (node_mailbox_trees_cmp): assertion failed: (ret != 0) 2016-12-06T12:19:30.678991+01:00 sauto dovecot: dsync-server(user01): Error: Raw backtrace: /usr/local/lib/dovecot/libdovecot.so.0(+0x92d70) [0x7f40f3cd1d70] -> /usr/local/lib/dovecot/libdovecot.so.0(+0x92e4e) [0x7f40f3cd1e4e] -> /usr/local/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f40f3c6d4e0] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x447584] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x447a57] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x447849] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x447849] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x447cc9] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x43a477] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x436e4e] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x437280] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x44c5af] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x52) [0x7f40f3ce54d2] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0xe7) [0x7f40f3ce6a07] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x3c) [0x7f40f3ce556c] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f40f3ce5728] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x41faae] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x421316] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x433b64] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x52) [0x7f40f3ce54d2] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run_internal+0xe7) [0x7f40f3ce6a07] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x3c) [0x7f40f3ce556c] -> /usr/local/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f40f3ce5728] -> /usr/local/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f40f3c73513] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x413b57] -> /lib64/libc.so.6(__libc_start_main+0xf5) [0x7f40f389eb15] -> dovecot/doveadm-server 10.0.0.1 user01 recv_mailbox_tree_deletes [0x413bf5] 2016-12-06T12:19:30.689038+01:00 sauto dovecot: dsync-server(user01): Fatal: master: service(doveadm): child 96318 killed with signal 6 (core dumps disabled) 2016-12-06T12:19:30.749074+01:00 sauto dovecot: dsync-local(user01): Error: read(server01.localdomain) failed: EOF (last sent=mailbox_delete, last recv=mailbox_tree_node)

Thanks, Kind regards, Gilles.