[logback-user] Is FixedWindowRollingPolicy useful to anyone?

ceki ceki at qos.ch
Fri Apr 19 15:49:14 CEST 2013

Hello all,

While fixing an issue related to FixedWindowRollingPolicy [1], the
question of whether FixedWindowRollingPolicy still served a purpose
came up. Indeed, since it is possible to archive log files by both
date and size [2], why is FixedWindowRollingPolicy needed, if at all?

Archiving in FixedWindowRollingPolicy involves as many file renames as
"MaxIndex". File renaming can be expensive on certain file systems. In
order to protect users from shooting themselves in the foot,
FixedWindowRollingPolicy caps MaxIndex to 12.

To cope with this issue, David Roussel suggested a different sliding
window policy [1], where index for archived files would be always
incremented by one and the file with the oldest (lowest) index would
be deleted on each rollover. This would avoid the file renaming
problem altogether. Again, is such a policy useful given that we
already have SizeAndTimeBasedFNATP [2]?

Your comments are welcome, especially if you are from the operational
side of things,

[1] http://jira.qos.ch/browse/LOGBACK-266
[2] http://logback.qos.ch/manual/appenders.html#SizeAndTimeBasedFNATP
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