Обсуждение: pgpool

First let me prefix this with "I'm not a DBA, I am a Linux Sys Admin"

Could someone provide a simple overview for me.

We have a postgres 9.0 server which is about to run out of diskspace.  I have built a new server and and set up a play virtual server so I can experiment with pgpool.
I can create a db on the new server and populate it.  Data appears on the virtual.  

So far so good.

My question(s)...  

1) how do I force the replication an existing database?  (preference is zero downtime)
2) where do i install pg-pool if I want to rebuild the original server and then have load balancing across the 2 physical servers?
3) do i need to change all my scripts to talk on the pg-pool (ie. 9999 ) port instead of postgres (5432) or do I make postgres listen on loopback and have pg-pool bind to the external ip (assuming its installed on the same server)?



The documents on the wiki seem to jump from the one line descriptions of what the software can do, straight into configuration. 

Is there a scenario documents anywhere, that can show pro's and con's of each setup mode and is written in non-dba speak.

On Sun, Aug 26, 2012 at 10:25 PM, David Pinkerton
<david.pinkerton@betteroff.net> wrote:
>
> First let me prefix this with "I'm not a DBA, I am a Linux Sys Admin"
>
> Could someone provide a simple overview for me.
>
> We have a postgres 9.0 server which is about to run out of diskspace.  I
> have built a new server and and set up a play virtual server so I can
> experiment with pgpool.
> I can create a db on the new server and populate it.  Data appears on the
> virtual.
>
> So far so good.
>
> My question(s)...
>
> 1) how do I force the replication an existing database?  (preference is zero
> downtime)
> 2) where do i install pg-pool if I want to rebuild the original server and
> then have load balancing across the 2 physical servers?
> 3) do i need to change all my scripts to talk on the pg-pool (ie. 9999 )
> port instead of postgres (5432) or do I make postgres listen on loopback and
> have pg-pool bind to the external ip (assuming its installed on the same
> server)?
>
>
>
> The documents on the wiki seem to jump from the one line descriptions of
> what the software can do, straight into configuration.
>
> Is there a scenario documents anywhere, that can show pro's and con's of
> each setup mode and is written in non-dba speak.

For emergency low-downtime switch of database from one server to
another, I'm wondering why you didn't explore the PITR route --
capturing a file system backup and grabbing the logs.  You can go even
further and do HS/SR for the replica.  pgpool (which i'm not very
familiar with) might also be a great tool for doing that -- I'm just
wondering what your thought process was.

merlin