Add skip-name-resolve=1 to disable lookups of hostnames to IPs. We
need to make sure all accounts are using IPs like 127.0.0.1 instead
of "localhost" now.
It seems that the usefulness of the query cache is diminishing in
recent years. If your cache is large then the time taken to scan
the cache can be longer than the SQL query itself.
See: https://haydenjames.io/mysql-query-cache-size-performance/