Horton

Re: Standalone synchronous master

Joshua D. Drake <jd@commandprompt.com>

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From: "Joshua D. Drake" <jd@commandprompt.com>
To: Jim Nasby <jim@nasby.net>, Hannu Krosing <hannu@2ndQuadrant.com>, Florian Pflug <fgp@phlo.org>, Josh Berkus <josh@agliodbs.com>
Cc: Bruce Momjian <bruce@momjian.us>, Andres Freund <andres@2ndquadrant.com>, Amit Kapila <amit.kapila16@gmail.com>, MauMau <maumau307@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, Kevin Grittner <kgrittn@ymail.com>, Heikki Linnakangas <hlinnakangas@vmware.com>, Simon Riggs <simon@2ndquadrant.com>, Rajeev rastogi <rajeev.rastogi@huawei.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2014-01-13T21:30:07Z
Lists: pgsql-hackers 
On 01/13/2014 01:14 PM, Jim Nasby wrote:
>
> On 1/13/14, 12:21 PM, Joshua D. Drake wrote:
>>
>> On 01/13/2014 10:12 AM, Hannu Krosing wrote:
>>>>> In other words, if we're going to have auto-degrade, the most
>>>>> intelligent place for it is in
>>>>> RepMgr/HandyRep/OmniPITR/pgPoolII/whatever.  It's also the *easiest*
>>>>> place.  Anything we do *inside* Postgres is going to have a really,
>>>>> really hard time determining when to degrade.
>>>> +1
>>>>
>>>> This is also how 2PC works, btw - the database provides the building
>>>> blocks, i.e. PREPARE and COMMIT, and leaves it to a transaction manager
>>>> to deal with issues that require a whole-cluster perspective.
>>>>
>>>
>>> ++1
>>
>> +1
>
> Josh, what do you think of the upthread idea of being able to recover
> in-progress transactions that are waiting when we turn off sync rep? I'm
> thinking that would be a very good feature to have... and it's not
> something you can easily do externally.

I think it is extremely valuable, else we have lost those transactions 
which is exactly what we don't want.

JD


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