Fix the RotatingFileHandler configuration of the daemon logger

[sphuber]

Fixes #3557

The logging configuration for the daemon did already include the
definition of a RotatingFileHandler, however, the logs were not
actually being rolled over when the maximum size was hit. The problem
was because the argument backupCount was not defined. As the python
documentation of the logging module states:

but if either of maxBytes or backupCount is zero, rollover never
occurs, so you generally want to set backupCount to at least 1,
and have a non-zero maxBytes.

Setting backupCount to 10, fixes the problem. The size of each file is
set to 10 MB. This should then keep at most 100 MB of log files for each
profile.

[giovannipizzi]

I'm approving, even if there is the risk that huge logs end up deleting all the history? Anyway I think the log often are mostly useful while noticing the problem, not much later.
Is this configurable, maybe?

[ltalirz]

Right - one question in general would be what should determine the maximum size of a file.
If I understand correctly, then the reason we introduce backup files here is because it is needed to have a file size limit at all.

In that sense, a backup count of 1 would do the job as well.

[greschd]

Right - one question in general would be what should determine the maximum size of a file.
If I understand correctly, then the reason we introduce backup files here is because it is needed to have a file size limit at all.

I think it is to have some granularity in how the backup is rolled. More, smaller, files mean that the amount of history deleted at a time is smaller for the same total log size. So the fluctuations in how much history is currently available at any given time are smaller.

[codecov]

Codecov Report

Merging #3891 into develop will not change coverage by %.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop    #3891   +/-   ##
========================================
  Coverage    77.17%   77.17%           
========================================
  Files          457      457           
  Lines        33778    33778           
========================================
  Hits         26067    26067           
  Misses        7711     7711           

Flag	Coverage Δ
#django	69.21% <ø> (ø)
#sqlalchemy	70.03% <ø> (ø)

Impacted Files	Coverage Δ
aiida/common/log.py	94.33% <ø> (ø)

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[sphuber]

I will merge this now and if there really is a need to make these values configurable, we can open a feature request issue to have support added for this through verdi config