Using ColdFusion builder 2018 to connect to a remote server which is mapped to a SQL database.

[Philip5FAC]

Our group has set up a ColdFusion Admin on a remote server. I have installed CF Builder 2018 on my PC. I am trying to connect to a SQL database which has been mapped on the remote server. I am in the RDS Dataview to access the data. I get an error 'Premature EOF encountered'. Is it possible to access the data on my PC from the remote server? What am i missing.

[Charlie Arehart · Accepted solution]

Philip, let's get one easy possibility out of the way first: are you saying you CAN connect via RDS to that server, and CAN see in your RDS view the list of datasources on that server? And is it that when you try to expand one of them, THAT's when you get the error?

I have seen some people get that "premature eof" error in just such a case, where the issue is that on the CF Admin of that remote server, the datasource you are trying to access (via RDS) doesn't even "verify". Have the person responsible for that remote CF Admin check that for you. If it does not verify in the CF Admin, then of course you won't be able to view it via RDS. And that could lead to this error (where the RDS feature is not passing back the details, to understand the actual cause).

But if instead you CANNOT yet see the list of databases on that server, or even can't connect to that server (in RDS), then that's entirely different, and there are SEVERAL things that can prevent one connecting to a given CF server from CFBuilder, because that RDS feature is indeed quite powerful (and a server allowing such connections is quite vulnerable, if considerable care is not taken). In fact, often such RDS access will be disabled, by default or by things that are "protecting" the server (CF or the box itself).

I actually wrote all the below before the first point above came to me. In case someone that's not it, I will share the rest here--for posterity, if nothing else. 🙂

So first, about the CF server (whose datasources you want to view in the RDS dataview feature of your local CFBuilder), is it that CF server a production or development CF instance? If it's a production one, it's unlikely you will be unable to connect to it via RDS from your CFBuilder, though even then it's not impossible.

To use an RDS connection from CFBuilder to a given CF server, you need several things:

• the CF server must have RDS enabled (a production server often will not). This is a setting in the CF Admin, in the security section.
• And of course, you would need to know the RDS password for that CF server (or they may use the CF Admin feature allowing different Admin/RDS users, who each have their own username and password. I wrote on that some years ago, but the feature works pretty much the same.)
• Next, you need to know the IP address, domain, or machine name for that server, which would generally be the same one as if you were to try to access the CF Admin itself remotely. And if that CF server is CF2016 or above, the CF Admin (and RDS) connection will be via a port (the CF built-in web server port). The person who runs CF on that machine should be able to tell you the IP address, domain, or machine name, as well as port, that they use to access the CF Admin.
• Even then, that ip address, domain, or machine name may NOT be accessible from off the server itself (indeed, most people just use 127.0.0.1 to access the CF Admin)
• Indeed, the CF admin itself will since CF2016 be set by default to be accessible only from the machine itself, which is controlled either at install or in the CF Admin Security page for "allowed IP addresses". They could/would have to add your IP address to that list, to be able to access either the CF Admin or RDS on that server. They can specify a range, or even allow all ip addresses ("*"), though of course that would be risky
• Even if you ARE able to access the ip, domain, or machine name, the next challenge will be the port used to access the Admin and RDS (which by default would be 8500). That port must be open to you to access from your machine, on which CFBuilder is running (a production server often will not). Typically a firewall would block such a non-standard port as 8500, so you would need to be added to that firewall also, though perhaps you are on a VPN or otherwise have full access to all ports on that machine
• if the request was going through a web server like IIS (on the CF server), rather than the CF built-in web server, you'd also need to make sure also that nothing in the web server is blocking requests into it, either from the outside, or entirely (some people setup IIS "request filtering" to block all access to URLs with paths like CFIDE).
• There may be still other things that I'm not thinking of. I will say that I wrote on things related to this in still more detail in a chapter for one of the CF Web App Construction Kit books, back in 2009. Much of it still applies today. And while it was more about the debugger, many of the same things about setting up CFBuilder for using the CF interactice step debugger feature still apply in setting up CFB for RDS.

Let us know how you get along, if you decide to keep trying.

[Charlie Arehart]

Hi, Philip. Thanks for marking my first answer as the "correct" one for you, but might you share what it was that was the issue for you, in case it may help others? If you prefer not to do that for some reason, ok. Either way, glad I could help.