[Pgpool-general] PgPool with Slony?

[Thomas Hallgren]

Hi Yoshiyuki,
thanks for the clarification. We are investigating several alternatives. 
Another that came up is to use pgpool and the Linux GFS. One reason for 
that is that we have things outside of the database (Lucene indexes in 
particular) that we would like to treat the same way. The question I'm 
asking myself is how big the negative performance impact would be. I 
googled for info and found some postings from Devrim Gündüz about this 
but I didn't find any conclusive info.

We are not trying to create a multi-master or anything like that. Our 
main objective is HA and if possible, multiple readers (where the reader 
can live with some latency). Does anyone know how well PostgreSQL 
performs on top of GFS?

Regards,
Thomas Hallgren

Yoshiyuki Asaba wrote:
> Hi,
>
> From: Thomas Hallgren <thomas at tada.se>
> Subject: [Pgpool-general] PgPool with Slony?
> Date: Tue, 30 Oct 2007 17:37:35 +0100
>
>   
>> I posted the questions below regarding Slony-I on their mailing list and 
>> got the suggestion to look at pgpool-II + slony + heartbeat. I see that 
>> a Pgpool-HA also exists that includes heartbeat. Given the requirements 
>> that I have, would Pgpool-HA + Slony-I be a good solution for me? Can I 
>> find some whitepapers or similar somewhere that outlines a solution like 
>> that?
>>     
>
> Pgpool-HA is scripts to monitor pgpool or pgpool-II. These run on
> heartbeat.
>
>   +---------------+                  +---------------+
>   |               |                  |               |
>   |  +---------+  |                  |  +---------+  |
>   |  |pgpool-HA|  |                  |  |pgpool-HA|  |
>   |  +---------+  |                  |  +---------+  |
>   |       |       |                  |       |       |
>   |       |       |                  |       |       |
>   |       v       |<---------------->|       v       |
>   |  +---------+  |                  |  +---------+  |
>   |  |pgpool-II|  |                  |  |pgpool-II|  |
>   |  +---------+  |                  |  +---------+  |
>   |               |                  |               |
>   +---------------+                  +---------------+
>       heartbeat                           heartbeat
>        (Active)                           (Standby)
>
> So pgpool-II + Slony-I + heartbeat + pgpool-HA is a good solution for
> you.
>
> Regards,
> --
> Yoshiyuki Asaba
> y-asaba at sraoss.co.jp
>