After the recent update to pt-table-checksum, I’ve seen a few
FAQs about it.
Q: is it still multi-threaded/parallel? A: No, that was a pile of
bugs and complexity. If you need to run the tool in parallel to
take advantage of powerful hardware, you can run several
instances, say, one per database.
Q: what chunk size should I use? A: None, let the tool adjust
itself dynamically.
Q: what if it skips a table or chunk because it’s oversized? A:
this should be rare unless you have tables without any indexes;
if you want to do the table in one chunk, run the tool again and
specify to checksum only that table, with an appropriately large
chunk size. This is one of the rare cases where you will need to
specify a chunk size.
Q: what commandline options should I use after upgrading? A: It
has sensible defaults for everything, and is designed to run
without any options at all in most cases. If you’re upgrading
from …
[Read more]