maria-developers team mailing list archive

[Kristian Nielsen <knielsen@xxxxxxxxxxxxxxx>]

Sachin Setiya <sachin.setiya@xxxxxxxxxxx> writes:

>>> I think that sounds like a very bad idea. The current_pos/slave_pos is the
>>> single biggest source of confusion regarding GTID. (In fact, I think it
>>> would be best to deprecate/eventually remove current_pos). Better not add
>>> to
>>> the confusion...
>>>
>>> If we remove current pos then how will how will master turned slave will
>> work ?
>>
> May be in this case user have to manually update gtid_slave_pos ?

Yes, that is one option, eg. SET GLOBAL gtid_slave_pos = @@gtid_binlog_pos;

Another option is to make an option to CHANGE MASTER that updates the
gtid_slave_pos _at_the_time_of_that_command_only_, like a one-shot
master_use_gtid=current_pos. Eg. something like:

  CHANGE MASTER TO master_host=xxx ... gtid_slave_pos_from_master=1;

The idea is that to make old master a slave, a CHANGE MASTER command will
usually be needed anyway. And _that_ is the point at which user wants the
binlog position to migrate to the slave position.

But with the current master_use_gtid=current_pos, this migration happens at
every future slave reconnect, which is very much not expected, and users are
all the time confused that a random manual transation on their slave later
makes GTID replication break.

 - Kristian.