Since MariaDB 10.3.4, when setting the system clock back in time (I tested by setting it back by 24h+), the NOW() and UNIX_TIMESTAMP() functions will not return the current, new, system time, but a fixed value from before when the system time was changed:
MariaDB [(none)]> SELECT now(), sysdate(), unix_timestamp();
|
+---------------------+---------------------+------------------+
|
| now() | sysdate() | unix_timestamp() |
|
+---------------------+---------------------+------------------+
|
| 2019-07-16 18:36:29 | 2019-07-16 18:36:29 | 1563302189 |
|
+---------------------+---------------------+------------------+
|
1 row in set (0.001 sec)
|
|
MariaDB [(none)]> \! date 07152000
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Mon Jul 15 20:00:00 UTC 2019
|
|
MariaDB [(none)]> SELECT now(), sysdate(), unix_timestamp();
|
+---------------------+---------------------+------------------+
|
| now() | sysdate() | unix_timestamp() |
|
+---------------------+---------------------+------------------+
|
| 2019-07-16 18:36:31 | 2019-07-15 20:00:00 | 1563302191 |
|
+---------------------+---------------------+------------------+
|
1 row in set (0.000 sec)
|
|
MariaDB [(none)]> SELECT sleep(2);
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+----------+
|
| sleep(2) |
|
+----------+
|
| 0 |
|
+----------+
|
1 row in set (2.000 sec)
|
|
MariaDB [(none)]> SELECT now(), sysdate(), unix_timestamp();
|
+---------------------+---------------------+------------------+
|
| now() | sysdate() | unix_timestamp() |
|
+---------------------+---------------------+------------------+
|
| 2019-07-16 18:36:31 | 2019-07-15 20:00:02 | 1563302191 |
|
+---------------------+---------------------+------------------+
|
Note how SYSDATE() correctly flips back to July 15th, while NOW() and UNIX_TIMESTAMP() are stuck with the last seen timestamp from 16th before the system time was set backwards with date
Bug
Critical
serg This seems to be related to your commit ac2d4d49a041c4b0657d24a9b3b697cbcfe69790.
Please have a look.