MySQL 5.7 log rotate empty We upgraded our Percona XtraDB servers from version 5.6 to 5.7, and we noticed that the rotation slow query log files created after the initial file are empty. Is this something known in 5.7? How can we resolve this issue?

We also noticed that 5.7 does not have the /etc/mysql/debian.cnf file anymore that used to contain a username and password. Can that have anything to do with this?

Below is an example of these rotational slow query logs on one of our 5.7 servers:

-rw-rw---- 1 mysql mysql  1383157070 Sep 20 16:11 db-erp-1-slow.log
-rw-rw---- 1 mysql mysql           0 Jul 27 06:36 db-erp-1-slow.log-20170728
-rw-rw---- 1 mysql mysql           0 Jul 28 06:30 db-erp-1-slow.log-20170729
-rw-rw---- 1 mysql mysql           0 Jul 29 06:43 db-erp-1-slow.log-20170730
-rw-rw---- 1 mysql mysql           0 Jul 30 06:50 db-erp-1-slow.log-20170731
-rw-rw---- 1 mysql mysql           0 Jul 31 06:43 db-erp-1-slow.log-20170801
-rw-rw---- 1 mysql mysql           0 Aug  1 06:37 db-erp-1-slow.log-20170802
-rw-rw---- 1 mysql mysql           0 Aug  2 06:48 db-erp-1-slow.log-20170803
-rw-rw---- 1 mysql mysql           0 Aug  3 06:42 db-erp-1-slow.log-20170804
-rw-rw---- 1 mysql mysql           0 Aug  4 06:43 db-erp-1-slow.log-20170805


So after the initial log file, db-erp-1-slow.log, the following log files are empty.
Do you restart mysql daily?  That could explain the new logs.

Check these VARIABLES:

log_output = FILE   -- or TABLE,FILE
slow_query_log = ON
slow_query_log_file = /...   -- some valid path, including filename
long_query_time = 1   -- or some small value


Perhaps the general log hit a limit, thereby triggering an internal call to FLUSH LOGS, which rotated all logs?