maria-developers team mailing list archive

[Henrik Ingo <henrik.ingo@xxxxxxxxxxxxx>]

On Tue, Mar 23, 2010 at 10:40 AM,  <seppo.jaakola@xxxxxxxxxxxxx> wrote:
>> At least the application of replicated transactions certainly should
>> not be part of each storage engine. From the engine point of view,
>> applying a set of replicated transactions should be "just another
>> transaction". For the engine it should not matter if a transaction
>> comes from the application, mysqldump, or a redundancy service. (There
>> may be small details: when the application does a transaction, we need
>> a new global txn id, but when applying a replicated transaction, the
>> id is already there.)
>>
>
> yes, but no. .e.g. Galera replication has this strange need to use
> prioritized transactions for applying. DBMS should have the responsibility
> to provide high priority sessions for replication appliers.

So Galera only works with the engines you have hacked to support it?
(Which I fear is InnoDB only?)

Like I said, we can still list a set of details the engine needs to
support, but in general of course we should be able to replicate from
any table/engine into any table/engine without having "replication
support" in each engine separately.

But on the face of it, your requirement does make sense for
synchronous replication. (And for the traditional asynchronous
replication, users generally want the lag to be a small as possible
too.)

henrik
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