`ejabberdctl start` nukes old logs

[catap]

Environment

• ejabberd version: 25.08
• Erlang version: Erlang (SMP,ASYNC_THREADS) (BEAM) emulator version 15.2.6
• OS: Linux OpenBSD
• Installed from: distro package

Configuration (only if needed): grep -Ev '^$|^\s*#' ejabberd.yml

loglevel: info
log_rotate_size: infinity
log_rotate_count: 10

Errors from error.log/crash.log

No errors

Bug description

When I start ejabberd via ejabberdctl start it remoes all old log files:

mx2$ ls -l /var/log/ejabberd/                                                                                                                               
total 528
-rw-r--r--  1 _ejabberd  _ejabberd  23210 Aug 22 17:46 ejabberd.log
-rw-r--r--  1 _ejabberd  _ejabberd  26588 Aug 22 15:00 ejabberd.log.0.gz
-rw-r--r--  1 _ejabberd  _ejabberd  28603 Aug 21 15:00 ejabberd.log.1.gz
-rw-r--r--  1 _ejabberd  _ejabberd  26600 Aug 20 15:00 ejabberd.log.2.gz
-rw-r--r--  1 _ejabberd  _ejabberd  30291 Aug 19 15:00 ejabberd.log.3.gz
-rw-r--r--  1 _ejabberd  _ejabberd  28371 Aug 18 15:00 ejabberd.log.4.gz
-rw-r--r--  1 _ejabberd  _ejabberd  26942 Aug 17 15:00 ejabberd.log.5.gz
-rw-r--r--  1 _ejabberd  _ejabberd  33254 Aug 16 15:00 ejabberd.log.6.gz
-rw-r--r--  1 _ejabberd  _ejabberd    215 Jun 27 05:47 error.log
mx2$ doas ejabberdctl stop
mx2$ ls -l /var/log/ejabberd/ 
total 544
-rw-r--r--  1 _ejabberd  _ejabberd  25111 Aug 22 17:47 ejabberd.log
-rw-r--r--  1 _ejabberd  _ejabberd  26588 Aug 22 15:00 ejabberd.log.0.gz
-rw-r--r--  1 _ejabberd  _ejabberd  28603 Aug 21 15:00 ejabberd.log.1.gz
-rw-r--r--  1 _ejabberd  _ejabberd  26600 Aug 20 15:00 ejabberd.log.2.gz
-rw-r--r--  1 _ejabberd  _ejabberd  30291 Aug 19 15:00 ejabberd.log.3.gz
-rw-r--r--  1 _ejabberd  _ejabberd  28371 Aug 18 15:00 ejabberd.log.4.gz
-rw-r--r--  1 _ejabberd  _ejabberd  26942 Aug 17 15:00 ejabberd.log.5.gz
-rw-r--r--  1 _ejabberd  _ejabberd  33254 Aug 16 15:00 ejabberd.log.6.gz
-rw-r--r--  1 _ejabberd  _ejabberd    215 Jun 27 05:47 error.log
mx2$ doas ejabberdctl start   
mx2$ ls -l /var/log/ejabberd/ 
total 80
-rw-r--r--  1 _ejabberd  _ejabberd  25351 Aug 22 17:47 ejabberd.log
-rw-r--r--  1 _ejabberd  _ejabberd    215 Jun 27 05:47 error.log
mx2$

[badlop]

This is reproducible in ejabberd 25.08, also 24.02 and probably any older releases that use logger instead of lagger.

Reproduction steps:

make relive
# press control+g and q
cd _build/relive

./ejabberdctl start && ./ejabberdctl started
./ejabberdctl stop && ./ejabberdctl stopped
(cd logs; cp ejabberd.log ejabberd.log.0.gz; ls)

# It shows: ejabberd.log  ejabberd.log.0.gz  error.log

echo "log_rotate_size: infinity" >> conf/ejabberd.yml

./ejabberdctl start && ./ejabberdctl started
ls logs
./ejabberdctl stop && ./ejabberdctl stopped

# It shows: ejabberd.log  error.log

The value of ejabberd's option log_rotate_size is passed to Logger's option max_no_bytes.

Logger is implemented in the Kernel library in OTP, seems it was first announced in Kernel 6.3 (included in Erlang/OTP 21.3)

The option max_no_bytes is documented in https://www.erlang.org/docs/28/apps/kernel/logger_std_h.html#content https://www.erlang.org/docs/28/apps/kernel/logger_disk_log_h.html#content

I couldn't find any explicit mention in the documentation that the old log files are removed. Maybe it makes sense somehow or is implicit after reading how the feature works...

[prefiks]

Looks like its explicit action in logger: https://github.com/erlang/otp/blob/master/lib/kernel/src/logger_std_h.erl#L707C18-L707C26 and looks like it was here from start. I also don't see any flag that could change that. Maybe worth filling bug in otp?