Re: Issues with Quorum Commit

On Wed, Oct 6, 2010 at 10:17, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> On 06.10.2010 11:09, Fujii Masao wrote:
>>
>> On Wed, Oct 6, 2010 at 3:31 PM, Heikki Linnakangas
>> <heikki(dot)linnakangas(at)enterprisedb(dot)com>  wrote:
>>>
>>> No. Synchronous replication does not help with availability. It allows
>>> you
>>> to achieve zero data loss, ie. if the master dies, you are guaranteed
>>> that
>>> any transaction that was acknowledged as committed, is still committed.
>>
>> Hmm.. but we can increase availability without any data loss by using
>> synchronous
>> replication. Many people have already been using synchronous
>> replication softwares
>> such as DRBD for that purpose.
>
> Sure, but it's not the synchronous aspect that increases availability. It's
> the replication aspect, and we already have that. Making the replication
> synchronous allows zero data loss in case the master suddenly dies, but it
> comes at the cost of availability.

That's only for a narrow definition of availability. For a lot of
people, having access to your data isn't considered availability
unless you can trust the data...

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 Magnus Hagander
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