[PostgreSQL error] failed to retrieve PostgreSQL server_version_num: connection refused

[nboddu009]

Hi Team,
Can someone help with installation issue in Ubuntu, I had installed Kong but when i am trying to start the kong, It is giving connection refused issue.
I had used https://docs.konghq.com/gateway/3.6.x/install/linux/ubuntu/ to install the kong.

user1$ sudo kong start
2024/05/09 22:22:55 [warn] ulimit is currently set to "1024". For better performance set it to at least "4096" using "ulimit -n"
2024/05/09 22:22:55 [warn] ulimit is currently set to "1024". For better performance set it to at least "4096" using "ulimit -n"
Error: [PostgreSQL error] failed to retrieve PostgreSQL server_version_num: connection refused

Run with --v (verbose) or --vv (debug) for more details
user1$ psql --version
psql (PostgreSQL) 14.12 (Ubuntu 14.12-1.pgdg20.04+1)

[samugi]

duplicate of #13010