← Back to team overview

maria-discuss team mailing list archive

Re: Does MariaDB support 2 level replication and crash recover from such situation?


On Tue, Dec 30, 2014 at 1:33 AM, Daniel Black
<daniel.black@xxxxxxxxxxxxx> wrote:
>> I am working on MariaDB with replication topology A->B->C,
>> in which B is the slave of A and also the master of C,
>> thus C contains data of both A and B.
>> and A, B would be modified by application
> To modify A and B they need to replicate to each other. If you do it it an incompatible way, like changing the same row on both at the same time, replication between them will break.
> Don't write to two nodes unless you have a fail proof way of preventing this.
>>, while C be read only.
>> now let B crash, I alter A to let it be the new master of C, and this time C
>> would be modified by application.
>> then after a period of time, B restart,
>> this time I need let C be the master of B, and I need B has the same data
>> with A and C,
>> thus the topology change from A->B->C to A->C->B.
>> Does this be possible?
> yes. Its sanity depends on more factors that what you;ve described.
> Ensure log-slave-updates is on all nodes.
> Using gtid replication will help you. Read the docs for this.

Note that even GTID will help here only if A and B use different
domain_id for all their transactions. And I guess C should use the
same domain_id as B when it becomes writable.