Re: Best approach for multi-database system

Interesting. This logicel (only remove WAL files after been applied)
should be available in PostgreSQL by default.
I mean, to have an option wheter every 15 minutes a master server query
slave for completeness, or slave notify master last successfully
imported WAL.


Atenciosamente,

Edson Carlos Ericksson Richter

Em 10/03/2016 16:56, Andy Colson escreveu:
> On 3/10/2016 1:41 PM, Edson Richter wrote:
>> Hi!
>>
>> Using async replication between geographically database servers. I've
>> some 9.3 and some 9.4 servers, so doesn't matter the version (the only
>> reason I've not migrated all to 9.4 yet is because I'm short on time).
>>
>> I've experienced some synchronization failures between Master-Slave
>> servers (for example, if connection is lost for 4 to 6 hours, the number
>> of wall keep segments may not suffice).
>> I've created some bash scripts that will reacreate the master-slave
>> using rsync, which seems to be farily easy - but really slow.
>> Depending on server size (130Gb for example) take really long on a 5Mbps
>> link - in some cases, all night long.
>>
>> This is the first approach: all databases in one server, and if I loose
>> the sync between master and slave, all data need to be transfered
>> between server and slave and is really slow.
>>
>> The other approach I've tested is to split each database in one cluster.
>> By using the second approach, I can resynch each server separeted (for
>> example 15Gb instead 130Gb).
>> This approach have the problema that it is needed to configure and
>> maintain another cluster for each database.
>>
>> Is there a best practice for multi-database systems with async
>> replication to avoid such "resync" problems?
>>
>>
>> Thanks for your orientation,
>>
>
> I wrote about my setup here:
>
> http://www.postgresql.org/message-id/548F3954.8040501@squeakycode.net
>
> Would be happy to answer questions.
>
> -Andy
>
>
>