Anyone happen to understand how (or if) DETERMINISTIC in Stored Programs
interacts with Replication?
On 10/28/11 12:03 AM, Johan De Meersman wrote:
> ----- Original Message -----
>> From: "Rick James"<rjames@stripped>
>>
>> The potential flaw in semi-sync is that it acks once the data gets to
>> the relay log; it does not wait for the write to be applied to the
>> table. Granted, it would take two serious crashes to cause loss of a
>> write.
> Correct, thank you :-)
>
> It amazes me how many people run replication, but how little is actually understood
> about it :-)
>
> MySQL's semi-synchronous feature is not that a quorum of slaves confirms the update
> (as Cassandra does, like Marcus points out); it is semi-synchronous because the slave must
> acknowledge that it has _received_ the update (ie, written to the relay log), whereas a
> fully synchronous replication requires that the slave acknowledges that it has _applied_
> the update.
>
> When the master writes statements to the binary log, most non-deterministic
> expressions (autoincrement, now(), ...) get replaced by the actual values that were
> applied; thus ensuring that the slave does indeed apply exactly the same data. Not *all*
> of those get translated, though - a typical example being "insert as select" where the
> select has no explicit ordering - and those cases, if you have them, can be accomodated by
> using row-based replication instead of statement-based. Look at the documentation before
> making a decision :-)
>
>
>
>
--
Rick James - MySQL Geek
