INNODB FREEZE

I want a new command in MySQL/InnoDB to freeze all filesystem activity in InnoDB… until I unfreeze it?

Why? I want mysqlhotcopy semantics for InnoDB.

Right now you can run FLUSH TABLES WITH READ LOCK and then xfs_freeze but it’s not very efficient or easy to code, and it’s pretty fragile.

INNODB FREEZE should not require a connection to remain open and should require an INNODB UNFREEZE to return IO to its normal state.

Further, when you copy away an underlying InnoDB database to a new server, crash recovery should NOT be required.

What really bothers me about the recent desire for MySQL features (triggers, etc) is that these type of features mean a LOT more to me. Operational competence in MySQL is very important and it seem the MySQL developers often forge this…

Drizzle and the InnoDB plugin are starting to show the way though….

Update:

I also want the ability to tell InnoDB to import a tablespace from a given .ibd created with innodb-file-per-table REGARDLESS of transaction identifiers and other information.

I know the tables is from another server, just import it already…


  1. MikeD

    I don’t know whether that’s the right kind of command for MySQL, but having a simplified, consistent and reliable way to take snapshots – both for full backup and for initializing a slave – would be very handy.
    Operational support should be a top feature category.

  2. We added an option in the v2 google patch to do that. ‘set global innodb_disallow_writes=on’ (or off) to toggle it. It blocks all filesystem activity from InnoDB except for reads — http://code.google.com/p/google-mysql-tools/wiki/Mysql5Patches. You don’t need it if you use ZFS or LVM.

  3. Mark.

    NICE… how did I miss that?

    …. so I assume it also blocks background dirty buffer flushing…. I guess that would quality as “all filesystem activity except for reads”.

    OK.. time to upgrade!

  4. It would be better to extract that feature from the v2 Google patch and into a branch that you want to use. MySQL 5.0.67 looks good.

  5. Yeah.. I’m going to blog about the monolithic nature of the V2 patch… would be nice if they were just a collection of smaller patches as they would be easier to land.

    But I guess begers can’t be choosers…






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