Increase file limit of a running process

Asking stupid questions and googling for them is fun some times...

Today I was asking myself if one could rise the file limit for a running MariaDB mysqld process online without restarting the database instance?

And I found an answer on serverfault: Set max file limit on a running process:

PID=$(pidof mysqld)

grep -e 'Max open files' -e Limit /proc/${PID}/limits 
Limit                     Soft Limit           Hard Limit           Units     
Max open files            1024                 4096                 files     

prlimit --pid $PID | grep -e NOFILE -e DESC
RESOURCE   DESCRIPTION                             SOFT      HARD UNITS
NOFILE     max number of open files                1024      4096 files

prlimit  --nofile --output RESOURCE,SOFT,HARD --pid ${PID}
RESOURCE SOFT HARD
NOFILE   1024 4096

sudo prlimit --nofile=2048:8192 --pid ${PID}

prlimit  --nofile --output RESOURCE,SOFT,HARD --pid ${PID}
RESOURCE SOFT HARD
NOFILE   2048 8192

Literature

prlimit(1)

See also:

• File Limit für MySQL hoch setzen
• Could not increase number of max_open_files