First incremental backup shows no increment on live Slave server?

I completed my first full backup of the server which went flawlessly, but I did my first incremental and it seems to have backed up the entire database again (not unexpected as all the tables are MyISAM). However the concern here is what the xtrabackup_checkpoints is reporting:
backup_type = incremental
from_lsn = 1377199387
to_lsn = 1377199387
last_lsn = 1377199387

Shouldn’t there be even a little bit of incrementing up here when backing up a live slave? I want to make sure I’m interpreting this right, but according to the documentation, I should see a larger number in the to_lsn and last_lsn than the starting number, right?

Thanks in advance.

Jim Yarrow

Hi jyarrow;

If you have an 100% MyISAM environment and/or no InnoDB/XtraDB tables were updated, then the LSN would not change. For MyISAM Innobackupex simply copies the files, so it doesn’t care what changed in those cases, and you get the full MyISAM table each time.

-Scott

Scott:

That’s not the case here. I erred when I said all the tables were MyISAM … 3 of the largest databases (of the 199 being backed up) are InnoDB so I should expect some incrementing. Or would that be no as this is the very first backup?

Jim

Hi jyarrow;

The full backup would be from zero to whatever LSN, and then if there are any InnoDB data changes you should see an increase in LSN for the incremental. So I would verify that data in the InnoDB tables you have are actually being updated in some way, and also that your incremental backup has the right full backup as the basedir. This is fairly straightforward to test if you have a test environment, so I’d go that route if you are unsure and want to play around with it to get comfortable with what is happening.

-Scott