After an upgrade to Ubuntu 20.04 LTS, my WordPress site is stuck in Maintenance mode. mySQL is trying to start with these same 10 lines repeating every couple of seconds in the /var/log/mysql/error.log
file. At least for me, a quick search of the term unknown variable 'query_cache_limit=1M'
only yields pages telling how to implement this parameter. How do I get it working again?
2020-11-12T16:12:25.733349Z 0 [Warning] [MY-011068] [Server] The syntax 'expire-logs-days' is deprecated and will be removed in a future release. Please use binlog_expire_logs_seconds instead.
2020-11-12T16:12:25.735469Z 0 [System] [MY-010116] [Server] /usr/sbin/mysqld (mysqld 8.0.22-0ubuntu0.20.04.2) starting as process 20068
2020-11-12T16:12:25.746199Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2020-11-12T16:12:26.131087Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2020-11-12T16:12:26.307241Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060, socket: /var/run/mysqld/mysqlx.sock
2020-11-12T16:12:26.370126Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2020-11-12T16:12:26.370481Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2020-11-12T16:12:26.377752Z 0 [ERROR] [MY-000067] [Server] unknown variable 'query_cache_limit=1M'.
2020-11-12T16:12:26.378449Z 0 [ERROR] [MY-010119] [Server] Aborting
2020-11-12T16:12:27.821939Z 0 [System] [MY-010910] [Server] /usr/sbin/mysqld: Shutdown complete (mysqld 8.0.22-0ubuntu0.20.04.2) (Ubuntu).