If a https connection that is configured to be keep alive connection. I try calling the https URL by opening a connection and closing it in a loop for 3 times.
I observe client port(http client) changes for every connection.

My understanding is as the connection is configured to be keep alive should it not use same client port?
Am I missing anything?

I have some question,
- is it require for the server supporting HTTP/2 protocol when we enabling this keep alive configuration ?
- How can we make sure if the traffic is balance between the member / origin address of the domain ?. Let say we have service discovery and there is 3 members active. When we doing keep alive connection which mean we will always connected to the 1 of the member right as persistent connection.

1. No HTTP/2 is not needed. As keep alive keeps the TCP connection alive.

2. Yes the connection will be persistent with one of the member. But usually service members are behind some kind of load balancer and we can configure at that end how long a particular connection should be alive.