[Pgpool-general] pgpool-ii hierarchy/structure

[Tatsuo Ishii]

> As I understand it, pgpool-ii is set up so that a backend of servers sit 
> and wait for communications from the client-facing pgpool-ii server. 
> Since pgpool acts as statement based replication, is it possible to set 
> up more than two pgpool-ii servers facing clients?
> 
> I am curious as this would be a method of load-balancing even further. 
> For example, if pgpool-ii server has a high load on it, it would make 
> sense to have another pgpool server serving requests, even if they're 
> pointing to the same backend servers. It would offer another level of 
> load balancing capability. 
> 
> Example in diagram form:  
> 
> level3. backend1, backend2, backend3   <----- backend postgres servers   
> level2. pgpool1, pgpool2 <---- pgpool servers working with backend1, 2 
> and 3   
> level1. web servers A,B,C,D,E,F <------ Clients of the pgpool servers  
> 
> Is this possible? Am I right in my belief that the backend postgres 
> servers themselves do not care or know if they're in a pool, that is, 
> the only bit of software that makes this logically into a pool of 
> servers is pgpool itself?

I believe the configuration above works.
--
Tatsuo Ishii
SRA OSS, Inc. Japan