My checklist for performing an in-place MySQL upgrade to 5.6.
In my previous post, I discussed the problem I had when doing an in-place MySQL upgrade from 5.5 to 5.6 when the database had been running with innodb_fast_checksum=1.
The solution was to use the MySQL 5.7 version of the tool innochecksum. Using this tool on a shutdown database, you can force the checksums on the innodb datafiles to be rewritten into either INNODB or CRC32 format.
Once the MySQL 5.6 upgrade is done, the 5.6 version of mysqld will be able to read the datafiles correctly and not fail with an error.
There is already plenty of good documentation on the MySQL website on how to upgrade from 5.x to 5.6.
My checklist for in-place upgrading to MySQL 5.6:
- Perform application and database performance testing on your test environment to make sure your application performance doesn’t get worse when running on MySQL 5.6.
- Make sure you have backups and verified that your backups are good aka you have restored databases from those backups.
- Check that all users have updated their passwords to use the new mysql password hash (plugin) Doc URL
- Organize downtime in advance.
- If running with innodb_fast_checksum=1, proceed with steps to replace the fast checksums with INNODB or CRC32.
Note: if you use CRC32, you will need to make sure your cnf file is updated for 5.6 to use innodb_checksum_algorithm = CRC32. This is because innodb_checksum_algorithm = INNODB is the default setting. See this post for a sample procedure.
- Run a quick search of all existing .cnf files to find any other system variables which have been removed and either replace or remove them.
- Run the in-place upgrade.
- Run mysql_upgrade, it will flag if it doesn’t need to be run again.
I am trying something new with a poll. Enjoy.