My QA server is clustered with Production despite using a different database

I have a Web API application that uses Hangfire. In production environment we have a cluster of 3 web servers, and for QA a single web server. The web.config for PROD contains a database connection string for the production HF database, and the QA web.config has a different database connection string.
When I go to the dashboard on one of the production servers, I see 4 servers listed: api1, api2, api3 and qa. How is this happening and how can I tell QA to not be part of this cluster? I assumed it was done based on which database was shared between the instances.

Servers are clustered by their backend storage as you expected. I’d double check your connection strings. The dashboard also lists what database it’s connected to in the footer so you can look at the QA one and make sure it’s connected to the QA DB/server.

Thanks for that confirmation. I have checked the connection strings and the DB connection info in dashboard footers, and everything looks right. Production is connected to production database and QA is connected to QA database.
The only thing I can think may have happened is that QA web app was at some point deployed with the Production connection string, and registered itself there. Now the question is how to remove it from the servers list… I can’t see any option to do this. It looks like I could just delete it from the [Hangfire.Server] table, taking usual precautions etc. Will that work?
[Edit - to be clear, on my QA server dashboard only the QA server is listed, but on Production I have all four]

If it joined once by accident it shouldn’t still show up in the server list. Once it was removed or turned off Hangfire would remove it from the list after not seeing a heartbeat for a period of time.

Does the QA server listed in production have a heartbeat?

Does the QA server listed in production have the same server name, port, and hash (mouse over name) as the QA server in QA?

My guess is there must be a 5th instance of your setup deployed somewhere (QA server pointing to production) and that’s the one showing up.

How embarrassing - you guessed right… Thanks for help.