We need to know if there's a health check page for DC and DS ? the page which we can hit without logging in that gives us a 200 code and tells us general health info.

For DC, the following URL is available in newer 8.10 releases:

http://<host &port>/decisioncenter/healthCheck

but that is not available for 8.9, also, no equivalent URL for RES console, even in 8.10.

For readiness probe, You can still use:

http://<host &port>/decisioncenter

For RES Console, use

http://<host &port>/res

to check the server is reachable without login.

for decision runner and HTDS, the following URLs can be used.

http://<host &port>/DecisionService

http://<host &port>/DecisionRunner