I have a JBoss app server and a Postgres database server on different machines. I'm troubleshooting TCP connections between them (because the app keeps running out of database connections).
I'm seeing this and it makes no sense:
- When I do a netstat on the database server, I see lots of established TCP connections from my app server.
- When I do a netstat on the app server, I see almost no established TCP connections to the database server.
The machines are VMware virtual machines running Centos, managed by a cloud provider (not AWS). There's no firewall between the machines (as per Too many established connections left open) which does seem like similar behaviour.
I don't know what else could cause this asymmetry?