I've recently been setting up a development image for SDL Web 8.5, and as it's only for use on my development rig, it's fair game to use Microsoft SQL Server Developer edition. It's not supported by SDL, but it's close enough to make it a reasonable risk for my purposes. I got the databases set up and the content manager installed OK, so I moved on to the content delivery stack. 

First I hacked together a database test script to make sure I had all the logins correct etc. I've done it this way for years, and you may have seen my blog about it quite a long time ago.  Everything seemed fine. 

I'd started with the Discovery service, and I'd configured the cd_storage_conf.xml with the relevant database settings I'd just tested. How hard could it be? Except that it didn't work. I got messages in the logs telling me to check my firewall. Doh! Off I went and opened up the firewall ports for my microservices (which I'd forgotten to do) and also 1433 for MSSQL. Still no joy. 

Somewhere along the way I'd also disabled loopback checking and double-checked a bunch of other things that can cause trouble. No joy. 

I went back to my database test script a few times. It uses a System.Data.SqlClient.SqlConnection to execute a simple command. The connection string specifies '(local)' as the server. I'd had trouble with using '(local)' in the cd_storage_conf.xml in a previous version of Tridion, so I had specified 'localhost' instead, and then when that didn't work, a different name that mapped to the same interface. Still nothing. 

The troubling thing was that the test script worked fine. Why was that, when Tridion's java stack had trouble doing the same thing? I should have cottoned on to this way earlier, but eventually I started checking to see if there was actually anything listening on 1433. No there wasn't. Well that helped. And then I started poking around in the network configuration of SQL Server. Sure enough: TCP/IP wasn't enabled. I'm still not sure if this is a Developer edition thing. I seem to recall having come across it before. I'm not the only one. Now that I know the answer, finding a suitable Stack Overflow answer is easy! Maybe I'd had trouble with SQLEXPRESS. 

Anyway, at least that explained why my test script worked OK. The SqlConnection client sees '(local)' and is then able to attempt a named pipes or shared memory connection as well as TCP/IP. The java client, on the other hand, doesn't have this repertoire of options and if TCP/IP fails, it's over.

Anyway - now it's fixed. Just time for a quick Note To Self, and on with the rest of my system.