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I'm having trouble connecting to graphql via the Prefect Server webUI. I can reach it on localhost:4200, &lt;ip&gt;:4200, and &lt;fully-qualified-name&gt;:4200, but I always get `Oops! It looks like something went wrong when trying to connect; make sure Prefect Server is running at the URL above and try again.`

Hey <@U01MEG3ET6C>,
Tough to say exactly where the issue lies, but you can configure your GQL endpoint directly<https://docs.prefect.io/orchestration/server/deploy-local.html#ui-configuration| in the UI >(under the *Getting Started* option at the top and clicking the *Prefect Server* tab) or by setting this endpoint directly in a config.toml file as described <https://docs.prefect.io/orchestration/faq/config.html#configuration-options|here>.

yeah, so, I get to that page but whatever value I put in there gives me the same error

Hmm, are the backend services running and are they accessible via network configurations?

what do you mean by network configurations?

as mentioned in OP, i can curl localhost:4200 from the box and get graphql to respond

I can also curl &lt;ip&gt;:4200 and get the response, and also &lt;fully-qualified-name&gt;:4200

so it's clear the graphql server is running and returning responses

I read through old comments in slack and tried increasing my instance size (running on EC2), but that didnt help

Definitely strange you are unable to connect the endpoints despite healthy responses. If you are on the latest version of Prefect, I think the best resource here is <https://www.youtube.com/watch?v=89W-jMVH410|this livestream> on configuring Server and its individual services.

when I get a connection failure on the prefect UI, where is that connection being made from? my browser to the graphql server? or the prefect server to graphql?

If the error is coming from the UI, then the browser is unable to connect with the GQL server.

so graphql needs to be exposed to all clients of the prefect server?

Also, the relevant part of that video for you will likely be around the 29 min mark, when Laura starts to connect Server services independently.

I think this <https://docs.prefect.io/orchestration/server/architecture.html|diagram> will help show which service is connecting to what, but that video really dives into it.

is apollo running on 8080 after running `prefect sever start`? or is that the UI?

Yes and <https://github.com/PrefectHQ/prefect/blob/master/src/prefect/config.toml|all default settings> are configured using the default config.toml file which can be overridden to meet your needs with a custom TOML file.

is there advice on setting up a load balancer (for me an ELB) in front of the UI? i think thats the root of my connection issues

Hmm, nothing official besides “you probably should go with Prefect Cloud” - Server wasn’t intended for Production setups with this level of configuration, so only experience can guide us here.