[systemd-devel] systemd-journald may crash during memory pressure

[vcaputo at pengaru.com]

Note the logs you've pasted portray a watchdog timeout which resulted in
SIGABRT and a subsequent core dump.

This is not really a journald "crash", and you can increase the watchdog
timeout or disable it entirely to make it more tolerant of thrashing.

What I presume happened is the system was thrashing and a page fault in
the mapped journal took too long to complete.

Regards,
Vito Caputo


On Thu, Feb 08, 2018 at 11:50:45PM +0100, Kai Krakow wrote:
> Hello!
> 
> During memory pressure and/or high load, journald may crash. This is
> probably due to design using mmap but it should really not do this.
> 
> On 32-bit systems, we are seeing such crashes constantly although the
> available memory is still gigabytes (it's a 32-bit userland running in a
> 64-bit kernel).
> 
> 
> [82988.670323] systemd[1]: systemd-journald.service: Main process exited, code=dumped, status=6/ABRT
> [82988.670684] systemd[1]: systemd-journald.service: Failed with result 'watchdog'.
> [82988.685928] systemd[1]: systemd-journald.service: Service has no hold-off time, scheduling restart.
> [82988.709575] systemd[1]: systemd-journald.service: Scheduled restart job, restart counter is at 2.
> [82988.717390] systemd[1]: Stopped Flush Journal to Persistent Storage.
> [82988.717411] systemd[1]: Stopping Flush Journal to Persistent Storage...
> [82988.726303] systemd[1]: Stopped Journal Service.
> [82988.844462] systemd[1]: Starting Journal Service...
> [82993.633781] systemd-coredump[22420]: MESSAGE=Process 461 (systemd-journal) of user 0 dumped core.
> [82993.633811] systemd-coredump[22420]: Coredump diverted to /var/lib/systemd/coredump/core.systemd-journal.0.3d492c866f254fb981f916c6c3918046.461.1518125377000000.lz4
> [82993.633813] systemd-coredump[22420]: Stack trace of thread 461:
> [82993.633814] systemd-coredump[22420]: #0  0x00007f940241d4dd journal_file_move_to_object (libsystemd-shared-237.so)
> [82993.633815] systemd-coredump[22420]: #1  0x00007f940241e910 journal_file_find_data_object_with_hash (libsystemd-shared-237.so)
> [82993.633816] systemd-coredump[22420]: #2  0x00007f940241fe81 journal_file_append_data (libsystemd-shared-237.so)
> [82993.633817] systemd-coredump[22420]: #3  0x0000556a343ae9ea write_to_journal (systemd-journald)
> [82993.633819] systemd-coredump[22420]: #4  0x0000556a343b0974 server_dispatch_message (systemd-journald)
> [82993.633820] systemd-coredump[22420]: #5  0x0000556a343b24bb stdout_stream_log (systemd-journald)
> [82993.633821] systemd-coredump[22420]: #6  0x0000556a343b2afe stdout_stream_line (systemd-journald)
> [82993.723157] systemd-coredum: 7 output lines suppressed due to ratelimiting
> [83002.830610] systemd-journald[22424]: File /var/log/journal/121b87ca633e8ac0016656680000001b/system.journal corrupted or uncleanly shut down, renaming and replacing.
> [83014.774538] systemd[1]: Started Journal Service.
> [83119.277143] systemd-journald[22424]: File /var/log/journal/121b87ca633e8ac0016656680000001b/user-500.journal corrupted or uncleanly shut down, renaming and replacing.
> 
> 
> -- 
> Regards,
> Kai
> 
> Replies to list-only preferred.
> 
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