ch.qos.logback.core.rolling.helper.TimeBasedArchiveRemover class 's clean method

 

public void clean(Date now) {
long nowInMillis = now.getTime();
// for a live appender periodsElapsed is expected to be 1
int periodsElapsed = computeElapsedPeriodsSinceLastClean(nowInMillis);
lastHeartBeat = nowInMillis;
if (periodsElapsed > 1)

{ addInfo("Multiple periods, i.e. " + periodsElapsed + " periods, seem to have elapsed. This is expected at application start."); }

for (int i = 0; i < periodsElapsed; i++)

{ int offset = getPeriodOffsetForDeletionTarget() - i; Date dateOfPeriodToClean = rc.getEndOfNextNthPeriod(now, offset); cleanPeriod(dateOfPeriodToClean); }

}

 

This method is invoked when deleting oldest log files. 

logback's log_max_history option is depended on it. 

computeElapsedPeriodsSinceLastClean(nowInMillis) method returns periodsElapsed value. 

other method return  32.  maybe ... 1 month. 

int computeElapsedPeriodsSinceLastClean(long nowInMillis) {
long periodsElapsed = 0;
if (lastHeartBeat == UNINITIALIZED)

{ addInfo("first clean up after appender initialization"); periodsElapsed = rc.periodBarriersCrossed(nowInMillis, nowInMillis + INACTIVITY_TOLERANCE_IN_MILLIS); periodsElapsed = Math.min(periodsElapsed, MAX_VALUE_FOR_INACTIVITY_PERIODS); }

else

{ periodsElapsed = rc.periodBarriersCrossed(lastHeartBeat, nowInMillis); // periodsElapsed of zero is possible for size and time based policies }

return (int) periodsElapsed;
}

 

is this right that i understand? 

 

I found this during I tested logback's log_max_history option. 

-> log_max_history=90 ,  today is 2021-12-22 
2021-08-22 ~ 2021-09-22  log files are deleted.

-> log_max_history=30, today is 2021-12-22
2021-10-21 ~ 2021-11-21  log files are deleted.

-> log_max_history=7, today is 2021-12-22
2021-11-13 ~ 2021-12-14  log files are deleted.

-> log_max_history=1,  today is 2021-12-22
2021-11-19 ~ 2021-12-20  log files are deleted.

 

I think there is the range... limit. 

Is there any one tested this option?