Callaghan's law et al

[James Wang]

Hi All,

Does  Callaghan's law still apply to Galera please?

Also, does it only apply for update the same records but not on insert?

Does the master (the one which has an insert/update/delete et al) wait all slaves (other masters) to complete the transaction?

I read "Certification based replication " - which seams advise that the master does not wait.

Please shed some light

Thanks a lot in advance

James

[alexey.y...@galeracluster.com]

On 2015-07-16 16:16, James Wang wrote:
> Hi All,
>
> Does Callaghan's law still apply to Galera please?

Yes, it's fundamental.

> Also, does it only apply for update the same records but not on insert?

If we are talking about inserting and deleting the same record, then
yes.

> Does the master (the one which has an insert/update/delete et al) wait
> all
> slaves (other masters) to complete the transaction?
> I read "Certification based replication " - which seams advise that the
> master does not wait.

Master waits only for data to be replicated (copied) to slaves.

> Please shed some light
>
> Thanks a lot in advance
> James

Hope that helps ;)

[James Wang]

Hi Alexey,

Thanks a lot.

So, the longest time the master wait is the network RTT of the slowest node?

BTW, is Galera version 4 ready to download please?  Nice meeting you at IBM in London of May 19th

Thanks indeed.