Horton

Re: Standalone synchronous master

Joshua D. Drake <jd@commandprompt.com>

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From: "Joshua D. Drake" <jd@commandprompt.com>
To: Andres Freund <andres@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, Kevin Grittner <kgrittn@ymail.com>, Bruce Momjian <bruce@momjian.us>, Heikki Linnakangas <hlinnakangas@vmware.com>, Simon Riggs <simon@2ndQuadrant.com>, Rajeev rastogi <rajeev.rastogi@huawei.com>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2014-01-08T22:52:07Z
Lists: pgsql-hackers 
On 01/08/2014 02:46 PM, Andres Freund wrote:

>> db0->db1 in synchronous mode
>>
>> The idea is that we know that data on db0 is not written until we know for a
>> fact that db1 also has that data. That is great and a guarantee of data
>> integrity between the two nodes.
>
> That guarantee is never there. The only thing guaranteed is that the
> client isn't notified of the commit until db1 has received the data.

Well ugh on that.. but that is for another reply.

>
> That's why you should configure a second standby as another (candidate)
> synchronous replica, also listed in synchronous_standby_names.

I don't have a response to this that does not involve a great deal of 
sarcasm.

Sincerely,

Joshua D. Drake

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