Thread: Doubts about replication..

On 04/19/2018 10:57 AM, Edmundo Robles wrote:
> 
> 
> I have several versions of postgres 9.4.5, 9.4.4, 9.4.15 (3), 9.5.3
> in different versions of Debian 7.6, 7.8, 7.11, 8.5 and 8.6.
> 
> I need to replicate the databases and I have clear that I must update 
> all to one version.
> My main question is, Do you  recommended me update to 9.6 or better 
> update to 10?.

If you have the choice go with 10 as you get an additional year of 
community support.

> 
> Actually, is not the goal have high availability . I will use 
> replication as simple backup.
> For reasons of $$$ I can only have 1 server in which I will replicate 
> the 6 databases.
> 
> Do you recommend using a postgres service for the 6 databases?, or 
> better, I think,   I must run  a postgres service in different ports, 
> for each  database?.

I am assuming you are going to be using some form of logical replication 
as binary replication will not work between Postgres major versions.

One cluster would be simpler to manage. The down side is that there are 
cluster(global) data e.g. roles that would be shared by all the 
databases. There is also the fact that everything is in one cluster and 
should it fail all six databases will be down. Running as separate 
clusters would give you some redundancy.
> 
> thanks in advance.
> regards!
> -- 
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com

Am 19.04.2018 um 19:57 schrieb Edmundo Robles:
> I will use replication as simple backup.

please keep in mind, replication is not a backup. All logical errors on 
the master (delete from table and forgot the where-condition) will 
replicated to the standby.


Andreas

-- 
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com

Hi,

If you want to reduce the amount of data lost, you might want to consider another type of backup : https://www.postgresql.org/docs/current/static/continuous-archiving.html

That awsome tool can also help you with it : https://pgbackrest.org/

Yes, you are right, the replication is not  a backup ;)  , actually   i backup  database  daily at  3:00 am but if database crash,  the amount  of data is  big!  that is the reason i want to  replicate to reduce  the data loss. By the way  a few days ago a job partner did a delete with no where.

On Thu, Apr 19, 2018 at 1:33 PM, Andreas Kretschmer <andreas@a-kretschmer.de> wrote:

Am 19.04.2018 um 19:57 schrieb Edmundo Robles:

I will use replication as simple backup.

please keep in mind, replication is not a backup. All logical errors on the master (delete from table and forgot the where-condition) will replicated to the standby.


Andreas

--
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com

--

-- 
Stefan FERCOT
http://dalibo.com - http://dalibo.org

On Thu, Apr 19, 2018 at 8:48 PM, Edmundo Robles <edmundo@sw-argos.com> wrote:
> Yes, you are right, the replication is not  a backup ;)  , actually   i backup  database  daily at  3:00 am but if
databasecrash,  the amount  of data is  big!  that is the reason i want to  replicate to reduce  the data loss. By the
way a few days ago a job partner did a delete with no where. 

Replication will happily replicate a delete with no where. Backup will
at least have the day starting point.

For this kind of things you need to do log-archiving + base backups.
With this you can use PITR to roll forward from the last full backup
to just before the delete.

Francisco Olarte.