pt-table-checksum 'skipping table .. too many rows' with stock params


I’m receiving the below error:

07-20T02:00:08 Skipping table dropbox.ProcessBootUps because on the master it would be checksummed in one chunk but on these replicas it has too many rows:
46198 rows on …
The current chunk size limit is 31014 rows (chunk size=15507 * chunk size limit=2.0).

With the following command-line:

pt-table-checksum --replicate=dropbox.checksums --nocheck-replication-filters --databases=dropbox --defaults-file=/root/.my.cnf

I’ve seen online that this error may result from messing with chunk params (e.g. setting chunk size equal to 0?), but I am not doing that. I have other tables with ~150 million rows and those seem to get processed fine.

I tried to poke around the source code a bit… it looks like “$o->get(‘explain’)” didn’t return true and in the else, “$nibble_iter->one_nibble()” returned true. I’m guessing that one_nibble() returns true if the table should be processed in one go… but why would that return true here if the table is too big?

Thanks for any advice.