I'm setting up a new PostgreSQL cluster, and want to use pgpool-II to load balance and pool connections... but I've not found anywhere that gives suggestions on pgpool server sizing.
Can someone suggest a formula for sizing the pgpool servers?
It's going to be a fairly simple setup, just load balancing and connection pooling with PostgreSQL streaming replication keeping the Read-Only servers in sync... no pgpool parallel query... no pgpool replication, etc:
8 x Web servers
2 x pgpool servers (using "watchdog" for high-availability, so active/passive setup)
4 x PostgreSQL database servers (8 CPU Cores, 16GB RAM. 1 x Read-Write, and 3 x Read-Only)
This is in a private VMware cloud setup, so I can't definitely say what a "CPU Core" is... or how fast, etc.
I was planning on using a small-ish server that has 2 x GigEthernet connections, and maybe 2G of ram... but I figure the most important thing is having high CPU to keep latency down and ensure the network ports can be flooded. I was going to start with 2 x CPU Cores and see how that goes, but it would be better if I wasn't shooting in the dark.
I'm going to do heavy-load testing later in the project, but I wanted to get close to the mark now... so any suggestions?
Thanks for your time.