Re: synch streaming replication question

How do I configure both standbys as ³synch² nodes?

Do I list both nodenames or ip addresesses in the postgresql.conf
synchronous_standyby_names entry?

My current entery looks like this:

synchronous_standby_names = 'keypg2,*'

John

On 2/22/16, 8:25 PM, "Thomas Munro" <thomas(dot)munro(at)enterprisedb(dot)com> wrote:

>On Tue, Feb 23, 2016 at 3:09 PM, Michael Paquier
><michael(dot)paquier(at)gmail(dot)com> wrote:
>> On Tue, Feb 23, 2016 at 6:43 AM, John Wiencek <jwiencek3(at)comcast(dot)net>
>>wrote:
>>
>>> I have a three node cluster using streaming replication configured as
>>> follows:
>>> One synch node and one asynch node.
>>> If my synch node is down the master node is hung until that node is
>>>brought
>>> back on line.
>>>
>>> Two questions:
>>> 1. Is this the expected action on my master? It makes sense if it is
>>>since
>>> the master is waiting for an ack from the synch node.
>>
>> Yes, when synchronous_commit = on, the default values that you should
>> have, the master will wait from standby the confirmation that the WAL
>> record for the commit has been flushed;
>>
>>http://www.postgresql.org/docs/devel/static/runtime-config-replication.ht
>>ml#RUNTIME-CONFIG-REPLICATION-MASTER
>>
>>> 2. Is there anyway to configure my cluster so I have a synch node but
>>>not
>>> have my master node ³HANG² if the synch node is down?
>>
>> You can do that at transaction level for example by disabling
>> synchronous_commit.
>
>Or you could configure both of your standbys as synchronous standbys.
>Only one of them will actually be a synchronous standby at a time, and
>the other one will take over that role if the first one is down, so
>your system won't hang but you'll still have the sync standby
>guarantee.
>
>--
>Thomas Munro
>http://www.enterprisedb.com