Question: Multiple pg clusters on one server can be reached with the standard port. - Mailing list pgsql-general

Hello all,

I am currently looking for a solution similar to Oracle Listener.

Current situation:
I have a system with multiple PostgreSQL clusters for different databases.
Each cluster is running on the same physical machine and is accessed through its own DNS alias and corresponding port.
I only have one single IP address available, and there is no possibility of obtaining additional addresses.

Here's an example:

   DNS ALIAS               Host
─> pgs1.server.net:5432 ─> PG_Cluster1@192.168.0.1:5432
─> pgs2.server.net:5433 ─> PG_Cluster2@192.168.0.1:5433
─> pgs3.server.net:5434 ─> PG_Cluster3@192.168.0.1:5434
─> pgs4.server.net:5435 ─> PG_Cluster4@192.168.0.1:5435
─> pgs5.server.net:5436 ─> PG_Cluster5@192.168.0.1:5436


Desired solution:
I still want to use the same system with different PostgreSQL clusters for the various databases.
These clusters are internally accessible through different ports.
However, I would like a service on the server to receive all external requests on port 5432 and forward them to the
correspondinginternal cluster based on the DNS alias.  
It would also be desirable if this service could provide additional features like connection pooling or other
functionalities.
Similar to a reverse proxy.

Here's an example:

   DNS ALIAS                 HOST
─> pgs1.server.net:5432 ─┐   ┌──────────────────┬──> PG_Cluster1@localhost:5433
─> pgs2.server.net:5432 ─┤   │                  ├──> PG_Cluster2@localhost:5434
─> pgs3.server.net:5432 ─┼─>─┤ 192.168.0.1:5432 ├──> PG_Cluster3@localhost:5435
─> pgs4.server.net:5432 ─┤   │                  ├──> PG_Cluster4@localhost:5436
─> pgs5.server.net:5432 ─┘   └──────────────────┴──> PG_Cluster5@localhost:5437


Is there a solution for this, and what are the advantages or limitations that arise from it?

Thank you in advance for your suggestions and help.

Regards,
   Michael