This topic follows this question on Launchpad
The original question was:
I would like to know if it is safe (from the replication point of view) to run pt-table-checksum toolkit in environments with a master-master MySQL configuration with slaves like this one:
A == B| |C D
 A is slave of B B is slave of A
 C is slave of A D is slave of B
The documentation of the pt-table-checksum do not discuss about such a configuration, unlike the pt-table-sync documentation for example.
In addition to the safety of the tool, I would like also to know if running pt-table-checksum on server A, automatically make the checksums on all the other servers.
The last question was:
I agree with your reply (that of Baron), just wondering why are you referring to a “passive master”.
The configuration I have explained is an active-active master-master replication where both A and B are active masters. The same arguments can be applied also in this case?
Thank you for your attention.