Mysql – Accuracy of thesqldbcompare vs other tools like pt-table-checksum

I do not understand why an application requires the MIXED replication format, as MIXED is equal to STATEMENT-based, but changing to ROW format when executing "unsafe" queries. So, a MIXED-compatible application should be compatible with both STATEMENT and ROW.

As you can see here, if the the format detected (server-side) is ROW or MIXED, it tries to change it dynamically for the session only. In your case, it complains about one of the slaves here (it requires SUPER privileges).

Assuming you do not have a 3-node chain replication, or you use the slave's binlog for anything, you can ignore the warning with --no-check-binlog-format. No need to change the my.cnf. The question is, will the session-only change to statement affect your "application that requires MIXED"? pt-table-checksum requires its own calculations to be done as statements, as a hash has to be calculated independently on the master and the slave independently and synchronously (not in time, but in relation with other queries).

"Diffs cannot be detected because no slaves were found."

That means that you are using the tool incorrectly -a single run must be done so that it creates checksums that are eventually consistent for the master and the slave.

Run pt-table-checksum only directed to the master, and create the appropriate permissions so that it can check the slave, too. Maybe it is a problem of authorization, maybe permissions (the lack of it), maybe the unproper slave detection (and you can change the detection method), but with that output, you are not using the tool in the documented way.

The different table checksums suggests that you are doing independent checksums on each server, or that they are not being performed correctly. You may still have schema differences, as it seems that one is using the primary key, while the other is not (hence the different chunks).