Re: Standalone synchronous master

On 01/10/2014 04:25 PM, Stephen Frost wrote:
> Adrian,
>
>
> * Adrian Klaver (adrian(dot)klaver(at)gmail(dot)com) wrote:
>> A) Change the existing sync mode to allow the master and standby
>> fall out of sync should a standby fall over.
>
> I'm not sure that anyone is argueing for this..

Looks like here, unless I am really missing the point:

http://www.postgresql.org/message-id/52D07466.6070005@commandprompt.com

"Proposed behavior:

db01->sync->db02

Transactions are happening. Everything is happy. Website is up. Orders
are being made.

db02 goes down. It doesn't matter why. It is down. db01 continues to
accept orders, allow people to log into the website and we can still
service accounts. The continuity of service continues.

Yes, there are all kinds of things that need to be considered when that
happens, that isn't the point. The point is, PostgreSQL continues its
uptime guarantee and allows the business to continue to function as (if)
nothing has happened.

For many and I dare say the majority of businesses, this is enough. They
know that if the slave goes down they can continue to operate. They know
if the master goes down they can fail over. They know that while both
are up they are using sync rep (with various caveats). They are happy.
They like that it is simple and just works. They continue to use
PostgreSQL. "

>
>> B) Create a new mode that does this without changing the existing sync mode.
>>
>> My two cents would be to implement B. Sync to me is a contract that
>> master and standby are in sync at any point in time. Anything else
>> should be called something else. Then it is up to the documentation
>> to clearly point out the benefits/pitfalls. If you want to implement
>> something as important as replication without reading the docs then
>> the results are on you.
>
> The issue is that there are folks who are argueing, essentially, that
> "B" is worthless, wrong, and no one should want it and therefore we
> shouldn't have it.

Well you will not please everyone, just displease the least.

>
> Thanks,
>
> Stephen
>

--
Adrian Klaver
adrian(dot)klaver(at)gmail(dot)com