On Mon, Aug 17, 2009 at 2:29 AM, Jorge Daine
Quiambao<cyb3rjorg3@yahoo.com> wrote:
> Hello,
>
> Can I ask you guys for suggestion on my replication requirements? I'm new to
> postgresql and the replication itself, so your inputs will be highly
> appreciated.
>
> My Situation:
>
> I have deployed a POS unit in our remote store using Openbravo POS as the
> software with a local installation of PostgreSQL for database. Now I will
> need to connect to this remote database from the central office to fetch
> latest data from the store and update products, prices and customer records.
> I would need to get the latest data from the store at least within 4-8hours.
>
> Here are the details about my requirements and info's about the nodes.
>
> Remote Location POS
> 256mb RAM, 640mhz Celeron CPU, 40gb HDD
> Openbravo POS with PostgreSQL (database size aprrox 15mb) on Ubuntu 8.10
> Sometimes Erratic, semi congested 384kbps connection shared w/ free wifi
> access. (If you'll ask why, we don't have a choice for a provider so far.)
>
> Central Server Database Virtual Machine
> 512mb RAM, 2.2ghz Shared AMD64 X2 CPU, 40gb HDD
> Openbravo POS with PostgreSQL on Ubuntu 8.10
> Dedicated 1mbps T1 connection
>
>
> Major Replication Requirements (from the Central Office side):
>
> 1. Apply updates on certain tables like products, customers, users and
> settings and commit on the remote location POS.
> 2. Query Sales, Transactions, Inventory and other tables for reporting
> purposes from POS.
> 3. Fetch update at least within 4-8 hours interval.
> 4. Generate Backups
>
> I know you only provide support in the community for free and I maybe asking
> too much, so I'm not expecting a lot. But I would appreciate any inputs
> regarding my situation.
I would look into slony or londiste for what you're doing. I'm not
familiar with londiste in the long range iffy connection realm, but
there's a lot you can do to monitor slony and send out alerts should
it fall behind etc. Slony is nice because it allows you to replicate
whichever tables in whichever direction you want, so you can have
master tables for some stuff central, and other tables that originate
on the remote sites and replicate to your big server back at the
office.
For backup look at either pg_dump (immediate take a backup program)
and PITR (allows continuous logging to prevent data loss).
