I want pulsar-discovery to come back.

**Is your enhancement request related to a problem? Please describe.**
Hi. I Newbie
I was using pulsar-discovery, but it wasn’t in 2.9.2, so why?
In my environment, pulsar-proxy is not able to handle traffic, so discovery is essential, so I hope you can help.
I switched to proxy last night, but I thought I was going to die because the Connection 150K ran out. (edited)

No files, tests, or entry points are named. Start by investigating why pulsar-discovery was absent in 2.9.2 and define what restoring it would require; then establish how discovery should address the reported proxy traffic and 150K-connection limitation.

Written by the indexing model from the issue text.