[Bug 1649168] Re: weekly log rotation is often a day late

[Doug Smythies]

** Description changed:

  Over the last few Ubuntu releases, the status file the logrotate
- generates and uses has been adding more and more detailed time stamp
- information.
+ generates and uses has added more detail to the time stamp information.
  
  In 12.04 it seems to only keep information to the day.
- In 14.04 it seems to only keep information to the hour.
+ In 14.04 it seems to keep information to the second.
  In 16.04 it seems to keep information to the second.
  
  However, the weekly section of the logrotate program calculates the time
  since the last rotation to the second with absolutely no jitter margin,
  and therefore as often as every other week, weekly logs that should
  rotate on Sunday do not rotate until Monday. I have 43 weeks of weekly
  rotation data, where on 17 of those weeks the rotation was on Monday and
  not Sunday. Note that the week after Monday rotation it will always
  rotate on Sunday due to "the current weekday is before the weekday of
  the last rotation" condition.
  
  Code segment:
  
-         case ROT_WEEKLY:
-             /* rotate if:
-                1) the current weekday is before the weekday of the
-                last rotation
-                2) more then a week has passed since the last
-                rotation */
-             state->doRotate = ((now.tm_wday < state->lastRotated.tm_wday)
-                                ||
-                                ((mktime(&now) -
-                                  mktime(&state->lastRotated)) >
-                                 (7 * 24 * 3600)));
+         case ROT_WEEKLY:
+             /* rotate if:
+                1) the current weekday is before the weekday of the
+                last rotation
+                2) more then a week has passed since the last
+                rotation */
+             state->doRotate = ((now.tm_wday < state->lastRotated.tm_wday)
+                                ||
+                                ((mktime(&now) -
+                                  mktime(&state->lastRotated)) >
+                                 (7 * 24 * 3600)));
  
- There is an upstream bug report at: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=825776
+ There is an upstream bug report at:
+ https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=825776
  which I will attempt to link in. It suggests introducing a 60 jitter allowance. I would make it more myself.
  
- I first noticed this issue during 16.04 development in 2016.02 (Feb).
+ I first noticed this issue during 16.04 development in 2016.02 (Feb). However, that computer had previously been a 12.04 server, so I do not have good data about 14.04.
  See also: https://ubuntuforums.org/showthread.php?t=2320149
  
  Do not ask me to run apport collect for this bug report, because it is
  not needed, and it never works for me anyhow.

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https://bugs.launchpad.net/bugs/1649168

Title:
  weekly log rotation is often a day late

Status in logrotate package in Ubuntu:
  New

Bug description:
  Over the last few Ubuntu releases, the status file the logrotate
  generates and uses has added more detail to the time stamp
  information.

  In 12.04 it seems to only keep information to the day.
  In 14.04 it seems to keep information to the second.
  In 16.04 it seems to keep information to the second.

  However, the weekly section of the logrotate program calculates the
  time since the last rotation to the second with absolutely no jitter
  margin, and therefore as often as every other week, weekly logs that
  should rotate on Sunday do not rotate until Monday. I have 43 weeks of
  weekly rotation data, where on 17 of those weeks the rotation was on
  Monday and not Sunday. Note that the week after Monday rotation it
  will always rotate on Sunday due to "the current weekday is before the
  weekday of the last rotation" condition.

  Code segment:

          case ROT_WEEKLY:
              /* rotate if:
                 1) the current weekday is before the weekday of the
                 last rotation
                 2) more then a week has passed since the last
                 rotation */
              state->doRotate = ((now.tm_wday < state->lastRotated.tm_wday)
                                 ||
                                 ((mktime(&now) -
                                   mktime(&state->lastRotated)) >
                                  (7 * 24 * 3600)));

  There is an upstream bug report at:
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=825776
  which I will attempt to link in. It suggests introducing a 60 jitter allowance. I would make it more myself.

  I first noticed this issue during 16.04 development in 2016.02 (Feb). However, that computer had previously been a 12.04 server, so I do not have good data about 14.04.
  See also: https://ubuntuforums.org/showthread.php?t=2320149

  Do not ask me to run apport collect for this bug report, because it is
  not needed, and it never works for me anyhow.

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