Something weird happened to MySQL while I was away today. The server was working, but no app is able to connect to it. Optimized and repaired all tables in all databases, rebooted server, tried to connect to it from a terminal... It does work, service is running without errors, but in several seconds when mysql service is restarted, no app can connect to it producing timeouts. All I see in error logs is:

2022-03-05T21:10:10.291857Z 0 [Warning] The syntax '--log_warnings/-W' is deprecated and will be removed in a future release. Please use '--log_error_verbosity' instead.

Any idea what to check and why it behaves like this? Was working well until an hour ago. Using Server version: 5.7.36-log MySQL Community Server (GPL) on Ubuntu Linux 20.04.4 64 bit.

  • The warning in your log does not appear to be related to the app connection issues. Perhaps the MySQL user that your app uses to connect had its password expire? I would try to test the connection using that user & password, using the mysql CLI, and see if it returns an error. See dev.mysql.com/doc/refman/5.7/en/password-management.html for MySQL 5.7 password expiration options. Mar 5 at 21:28
  • you should post the error message that your app delivers also only errors would be relevant for the happenings
    – nbk
    Mar 5 at 23:06
  • I know the error is not related. The apps show no related errors, either. Now I woke up and it seems to be working. Very strange behavior. I hope it will work as usual now, but it bothers me. How come this even happened? I would like to figure it out and prevent it from ever happening again.
    – svet0slav
    Mar 6 at 5:33
  • Are you connecting via localhost or TCP/IP?
    – Rick James
    Mar 6 at 6:06
  • @RickJames, i connect to localhost. Maybe the problem is too many connections or I/O problem? Disk array is 10 SSDs in RAID 10. Now it came to me I should have checked with iotop. Server has a ton of apps on it. Like 400. Maybe it is time I migrate some to another one.
    – svet0slav
    Mar 7 at 7:02

1 Answer 1


That warning message exists in 5.7 to inform you that it will become invalid in some future release (specifically, 8.0).

It may actually not be a problem when you upgrade. But, since I can't tell what is generating the mysqld command, I cannot say for sure.

As already mentioned, it is unrelated to the CLI (mysql).

  • I understand. Thanks! For now I would like to stick to 5.7.
    – svet0slav
    Mar 7 at 7:06
  • Appears to be php-fpm problem. After some adjustments to the config of OS, nginx and fpm, the problem is no more. I figured it out because there were apps not using MySQL and no database at all, which had the same problem.
    – svet0slav
    Mar 10 at 6:06

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