maria-discuss team mailing list archive

[Sergei Golubchik <serg@xxxxxxxxxxx>]

Hi, Gordan,

Would it work if you install "mysql_json" plugin in the MariaDB and then
replicate MySQL->MariaDB?

I didn't try myself, but I've checked the sources and it appears that it
was supposed to work.

If it won't - please, report it as a bug.

On May 29, Gordan Bobic wrote:
> On this page:
> https://mariadb.com/kb/en/json-data-type/
> 
> it states:
> If you must use row-based replication and cannot change the MySQL
> master from JSON to TEXT, you can try to introduce an intermediate
> MySQL slave and change the column type from JSON to TEXT on it. Then
> you replicate from this intermediate slave to MariaDB.
> 
> I can confirm that this does not work with MySQL 5.7. If you have a
> 5.7 master and you replicate to 5.7 slave, and you convert the slave's
> json columns to longtext, replication fails with this error:
> 
> "Column X of table 'dbname.tablename' cannot be converted from type
> 'json' to type 'longtext'"
> 
> Using longblob doesn't work either.
> 
> So it seems there is currently no viable solution for replicating
> anything that involves JSON columns from MySQL to MariaDB.
> 
Regards,
Sergei
VP of MariaDB Server Engineering
and security@xxxxxxxxxxx