Upgrade from MySQL 8.0.33 to 8.0.41 this morning on production.
Everything went smoothly... until:
Lock timeout when upgrading an intermediate primary in a ClusterSet. It looks like https://bugs.mysql.com/bug.php?id=100242. I know that kill -9 has been used in the past (yes, MySQL can be challenging and it's the only solution), so let's re-initialize the host. 6TB of data, it's going to be long but we have no choice at this point.
The Percona Server version of MySQL Shell doesn't support the Javascript interface anymore. The official documentation has Javascript examples everywhere but not Python. I had to guess and learn the Python equivalent in emergency.
Then if we define a "localAddress" to "Cluster.add_instance", MySQL tries to use the deprecated "XCOM" communication stack instead of "MYSQL". If you have errors on port 33061, you should remove the localAddress and/or use the "MYSQL" communication stack https://dev.mysql.com/doc/mysql-shell/8.0/en/shell-admin-api-communication-stack.html
Every time the service is started, it takes 30 seconds to initialize the InnoDB buffer pool because the host has 1TB of RAM.
For an unknown reason, the mandb process takes multiple minutes when upgrading a package.
Time is really long when you do upgrades.