Horton

Re: Standalone synchronous master

MauMau <maumau307@gmail.com>

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From: "MauMau" <maumau307@gmail.com>
To: "Hannu Krosing" <hannu@2ndQuadrant.com>, "Andres Freund" <andres@2ndquadrant.com>, "Joshua D. Drake" <jd@commandprompt.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>
Date: 2014-01-09T15:15:34Z
Lists: pgsql-hackers 
From: "Hannu Krosing" <hannu@2ndQuadrant.com>
> On 01/09/2014 01:57 PM, MauMau wrote:
>> Let me ask a (probably) stupid question.  How is the sync rep
>> different from RAID-1?
>>
>> When I first saw sync rep, I expected that it would provide the same
>> guarantees as RAID-1 in terms of durability (data is always mirrored
>> on two servers) and availability (if one server goes down, another
>> server continues full service).
> What you describe is most like A-sync rep.
> 
> Sync rep makes sure that data is always replicated before confirming to
> writer.

Really?  RAID-1 is a-sync?

Regards
MauMau