Horton

Re: Synchronous replication - patch status inquiry

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>

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From: Heikki Linnakangas <heikki.linnakangas@enterprisedb.com>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Fujii Masao <masao.fujii@gmail.com>, Robert Haas <robertmhaas@gmail.com>, David Fetter <david@fetter.org>, Bruce Momjian <bruce@momjian.us>, fazool mein <fazoolmein@gmail.com>, pgsql-hackers@postgresql.org
Date: 2010-09-02T12:15:17Z
Lists: pgsql-hackers 
On 02/09/10 15:03, Simon Riggs wrote:
> On Thu, 2010-09-02 at 19:24 +0900, Fujii Masao wrote:
>> On Wed, Sep 1, 2010 at 7:23 PM, Heikki Linnakangas
>> <heikki.linnakangas@enterprisedb.com>  wrote:
>>> That requirement falls out from the handling of disconnected standbys. If a
>>> standby is not connected, what does the master do with commits? If the
>>> answer is anything else than acknowledge them to the client immediately, as
>>> if the standby never existed, the master needs to know what standby servers
>>> exist. Otherwise it can't know if all the standbys are connected or not.
>>
>> Thanks. I understood why the registration is required.
>
> I don't. There is a simpler design that does not require registration.
>
> Please explain why we need registration, with an explanation that does
> not presume it as a requirement.

Please explain how you would implement "don't acknowledge commits until 
they're replicated to all standbys" without standby registration.

-- 
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com