Mikhail Gavrilov

Does it happen often?

What makes you think it's related to the feedback plugin?
Did you try to disable the feedback plugin to see if it helps?

Did you check system logs to see if there were any disk-related errors around this time?

Please attach your my.cnf file(s) (or, if you already did it in other JIRA reports, please point at them).

Thanks

> Does it happen often?
> What makes you think it's related to the feedback plugin?
Happens on every new database instance when if feedback plugin was enabled before..

> Did you try to disable the feedback plugin to see if it helps?
I never seen this problem before.

> Did you check system logs to see if there were any disk-related errors around this time?
dmesg log not contain disk error + this reproducible on another machines.

> Please attach your my.cnf file(s) (or, if you already did it in other JIRA reports, please point at them).
config files in attached in etc.tar.gz archive
in sql.log log from application.
application catch this error as error "MySQL server has gone away'"

Mikhail Gavrilov,

Could you please check the dynamics of open file descriptors with and without the feedback plugin.
Also, does it only happen when the plugin throws errors like the ones in the attached error log, or is it unrelated?

And does it only happen on Fedora 23, as you initially specified? As I understand, it's barely beta, did you check it for known bugs about leaking file descriptors and alike?

Thanks.

> Could you please check the dynamics of open file descriptors with and without the feedback plugin.
How I can do check the dynamics of open file descriptors? What you means?
Do

# lsof -u mysql | wc -l

and compare result with

SHOW VARIABLES WHERE variable_name = 'open_files_limit'

???

I think if we exceed count of open files we see another error:

SQLSTATE[HY000]: General error: 1018 Can't read dir of '.' (errno: 24 "Too many open files")

> Also, does it only happen when the plugin throws errors like the ones in the attached error log, or is it unrelated?
I never see this before I started use feedback plugin. I am not sure that this is related, but if it unrelated I not seen another error's in MariaDB log files.

> And does it only happen on Fedora 23, as you initially specified? As I understand, it's barely beta, did you check it for known bugs about leaking file descriptors and alike?
No, first time I see this problem when init database with feedback plugin on Fedora 22.