I upgraded by dev box from ubuntu 18 to ubuntu 20. Now running the full test_mysql
takes 4 hours.


https://dba.stackexchange.com/questions/27808/mysql-table-creation-insanely-slow

helped to get an idea of where the time was spent, but there doesn't seem to be a solution.

This is unlikely to be a production issue as table creation/mutation is infrequent but...
There may be some tuning of mysqld.conf that helps but... I am using the mysqld
change defined in the workflows that sped thing up significantly under 5.x.

Hmm,

   https://www.percona.com/blog/optimizing-innodb-for-creating-30000-tables-and-nothing-else/

reports using libeatmydata. Starting mysqld as:

  sudo -u mysql eatmydata mysqld &

(after creating /var/run/mysqld with user:group mysql.mysql)
and running and it completes in not ~14000 seconds but ~411.

Mysql

   224 passed in 411.67 second

with load average in the mid 2's not mid 4's. Still have I/O waits in the 80/90 on some cpus
(2 core 2 thread).

For comparison postgresql:

   456 passed in 507.34 seconds

Will see if mysqltuner can help.