Description:
We have 3 docs that explain about shutdowns during upgrades.
i. Upgrading MySQL Binary or Package-based Installations on Unix/Linux - https://dev.mysql.com/doc/refman/8.0/en/upgrade-binary-package.html
ii. Preparing Your Installation for Upgrade - https://dev.mysql.com/doc/refman/8.0/en/upgrade-prerequisites.html
iii. Variable - sysvar_innodb_fast_shutdown - https://dev.mysql.com/doc/refman/8.0/en/innodb-parameters.html#sysvar_innodb_fast_shutdown
From doc i.
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If you normally run your MySQL server configured with innodb_fast_shutdown set to 2 (cold shutdown), configure it to perform a fast or slow shutdown by executing either of these statements:
SET GLOBAL innodb_fast_shutdown = 1; -- fast shutdown
SET GLOBAL innodb_fast_shutdown = 0; -- slow shutdown
With a fast or slow shutdown, InnoDB leaves its undo logs and data files in a state that can be dealt with in case of file format differences between releases.
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It does not specifically talk about doing slow shutdowns for major version upgrades to 8.0.
From doc ii.
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If upgrade to MySQL 8.0 fails due to any of the issues outlined above, the server reverts all changes to the data directory. In this case, remove all redo log files and restart the MySQL 5.7 server on the existing data directory to address the errors. The redo log files (ib_logfile*) reside in the MySQL data directory by default. After the errors are fixed, perform a slow shutdown (by setting innodb_fast_shutdown=0) before attempting the upgrade again.
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Again, the above does not mention slow shutdown as a pre-requisite for major version upgrades. It instead mentions about setting the parameter if upgrade fails.
From doc iii.
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Use the slow shutdown technique before upgrading or downgrading between MySQL major releases, so that all data files are fully prepared in case the upgrade process updates the file format.
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So we have doc iii. clearly mentioning about using upgrades for slow shutdowns. However, there is no explicit mentions of them in docs i. or ii.
Ask: Clarify and have consistent messaging on all 3 docs mentioned above if innodb_fast_shutdown is a mandatory requirement for major version upgrades.
How to repeat:
NA
