From: | Amit Langote <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> |
---|---|
To: | Michael Paquier <michael(dot)paquier(at)gmail(dot)com>, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> |
Cc: | Beena Emerson <memissemerson(at)gmail(dot)com>, PostgreSQL mailing lists <pgsql-hackers(at)postgresql(dot)org> |
Subject: | Re: Support for N synchronous standby servers - take 2 |
Date: | 2015-06-26 08:04:43 |
Message-ID: | 558D079B.4040208@lab.ntt.co.jp |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Hi,
On 2015-06-25 PM 01:01, Michael Paquier wrote:
> On Thu, Jun 25, 2015 at 12:57 PM, Fujii Masao wrote:
>> On Thu, Jun 25, 2015 at 12:15 PM, Michael Paquier wrote:
>>> and that's actually equivalent to that in
>>> the grammar: 1(AAA,BBB,CCC).
>>
>> I don't think that they are the same. In the case of 1(AAA,BBB,CCC), while
>> two servers AAA and BBB are running, the master server may return a success
>> of the transaction to the client just after it receives the ACK from BBB.
>> OTOH, in the case of AAA,BBB, that never happens. The master must wait for
>> the ACK from AAA to arrive before completing the transaction. And then,
>> if AAA goes down, BBB should become synchronous standby.
>
> Ah. Right. I missed your point, that's a bad day... We could have
> multiple separators to define group types then:
> - "()" where the order of acknowledgement does not matter
> - "[]" where it does not.
For '[]', I guess you meant "where it does."
> You would find the old grammar with:
> 1[AAA,BBB,CCC]
>
Thanks,
Amit
From | Date | Subject | |
---|---|---|---|
Next Message | Michael Paquier | 2015-06-26 08:18:38 | Re: Support for N synchronous standby servers - take 2 |
Previous Message | Oskari Saarenmaa | 2015-06-26 07:52:26 | thread_test's sched_yield requires -lrt on solaris |