Inserting a fractional second into MySQL 5.6 and MariaDB yields different results, and as a consequence, replicating from a MySQL 5.6 master into a MariaDB 10 slave creates an inconsistent slave.
On Oracle/Percona MySQL 5.6 the value is rounded:
On MariaDB 10 it is not:
Inconsistent MariaDB slave test:
This issue affects both datetime and timestamp column types.
MariaDB should have same behaviour regarding fractional seconds as Oracle and Percona, or interoperability is compromised. For example, a pt-table-checksum always fails due to these rounding differences when comparing a MariaDB slave against a non MariaDB master.
Until this bug is fixed we will be unable to use multi source replication, which was the primary reason for us to use MariaDB.