Maximum Availability Architecture(MAA) for PostgreSQL

Hi everyone.

I posted this in the SG mailing list but there wasn't any response. Thus, I
decided to repost it here.

Anyone who is familiar with Oracle database would have heard of the Oracle
Maximum Availability Architecture where Oracle uses a range of products to
prevent the databases from suffering planned and unplanned outages.

In the PostgreSQL world, what do you guys think would be the equivalent?

Attached is a diagram I have thought of. Clusters of pg-pool2 used to load
balance the connection in and for connection failover when a DB crashes.
Between master and slave, sync replication is being used for zero-data-loss.

Let me know your thoughts!

Cheers!

--
Regards,
Ang Wei Shan