Signal 11: errors in dovecot log

[jrse]

During imaptest killed processes with Signal 11 are in the log
Signal 11 Errors in Dovecot log after imaptest.

To Reproduce
Steps to reproduce the behavior:

1. Setup CephCluster
2. Use cephfs as rbox Mailbox location
3. use imaptest https://github.com/ceph-dovecot/imaptest
4. let it run

Expected behavior
no signal 11 messages in the log

Logfiles, screenshots
Nov 05 14:10:51 imap(t39): Fatal: master: service(imap): child 28754 killed with signal 11 (core dumped)
Nov 05 14:11:28 imap(t406): Fatal: master: service(imap): child 31532 killed with signal 11 (core dumped)
Nov 05 14:11:30 imap(t370): Fatal: master: service(imap): child 29893 killed with signal 11 (core dumped)
Nov 05 14:11:31 lmtp(t431): Fatal: master: service(lmtp): child 28720 killed with signal 11 (core dumped)
Nov 05 14:11:43 imap(t609): Fatal: master: service(imap): child 31830 killed with signal 11 (core dumped)
Nov 05 14:11:43 imap(t526): Fatal: master: service(imap): child 31817 killed with signal 11 (core dumped)
Nov 05 14:11:48 imap(t706): Fatal: master: service(imap): child 32055 killed with signal 11 (core dumped)
Nov 05 14:11:48 imap(t508): Fatal: master: service(imap): child 31886 killed with signal 11 (core dumped)
Nov 05 14:11:48 imap(t494): Fatal: master: service(imap): child 32478 killed with signal 11 (core dumped)
Nov 05 14:11:49 lmtp(t587): Fatal: master: service(lmtp): child 28757 killed with signal 11 (core dumped)
Nov 05 14:11:49 lmtp(t631): Fatal: master: service(lmtp): child 28718 killed with signal 11 (core dumped)
Nov 05 14:11:49 imap(t488): Fatal: master: service(imap): child 31711 killed with signal 11 (core dumped)
Nov 05 14:11:50 imap(t708): Fatal: master: service(imap): child 31885 killed with signal 11 (core dumped)
Nov 05 14:11:50 lmtp(t678): Fatal: master: service(lmtp): child 28755 killed with signal 11 (core dumped)
Nov 05 14:11:51 imap(t846): Fatal: master: service(imap): child 32610 killed with signal 11 (core dumped)
Nov 05 14:11:52 lmtp(t623): Fatal: master: service(lmtp): child 31822 killed with signal 11 (core dumped)
Nov 05 14:11:52 imap(t525): Fatal: master: service(imap): child 31610 killed with signal 11 (core dumped)
Nov 05 14:11:52 imap(t659): Fatal: master: service(imap): child 31829 killed with signal 11 (core dumped)
Nov 05 14:11:52 imap(t590): Fatal: master: service(imap): child 31489 killed with signal 11 (core dumped)
Nov 05 14:11:53 lmtp(t729): Fatal: master: service(lmtp): child 28750 killed with signal 11 (core dumped)
Nov 05 14:11:53 imap(t933): Fatal: master: service(imap): child 414 killed with signal 11 (core dumped)
Nov 05 14:11:54 imap(t996): Fatal: master: service(imap): child 381 killed with signal 11 (core dumped)
Nov 05 14:11:54 imap(t885): Fatal: master: service(imap): child 417 killed with signal 11 (core dumped)
Nov 05 14:11:54 imap(t736): Fatal: master: service(imap): child 415 killed with signal 11 (core dumped)
Nov 05 14:11:57 lmtp(t681): Fatal: master: service(lmtp): child 28767 killed with signal 11 (core dumped)
Nov 05 15:14:44 imap(t971): Fatal: master: service(imap): child 10434 killed with signal 11 (core dumped)
Nov 05 15:24:23 imap(t433): Fatal: master: service(imap): child 8690 killed with signal 11 (core dumped)
Nov 05 15:29:01 imap(t399): Fatal: master: service(imap): child 19535 killed with signal 11 (core dumped)
Nov 05 15:41:43 imap(t221): Fatal: master: service(imap): child 9028 killed with signal 11 (core dumped)
Nov 05 16:02:48 imap(t237): Fatal: master: service(imap): child 20012 killed with signal 11 (core dumped)
Nov 05 19:21:55 imap(t547): Fatal: master: service(imap): child 19364 killed with signal 11 (core dumped)
Nov 05 20:36:28 imap(t577): Fatal: master: service(imap): child 14710 killed with signal 11 (core dumped)
Nov 05 21:15:42 imap(t332): Fatal: master: service(imap): child 447 killed with signal 11 (core dumped)
=> In debug and info log are not obvious message which could explain this. The error seems to occur when client does a select on the box...

Server (please complete the following information):

• OS: ubuntu
• Ceph Version luminous
• Dovecot Version 2.2.21
• plugin version: > 0.0.13

Client (please complete the following information):

• used client imaptest
• Version https://github.com/ceph-dovecot/imaptest

Logfiles:

dovecot-debug.log.t332.txt