Database Connection Error But Database is Fine

I’m on WP 3.0.5 Multisite with about 300 blogs. We’ve been live for almost 2 years.

This morning around 10:00, we got “Error Establishing Database Connection” on the screens. And it didn’t go away. The site worked great up until then. No upgrades or file changes in the last couple of days.

I’m the only one who accesses the files. Nothing was changed, I wasn’t even in there. And, according to access logs, nobody else was either.

Here’s the rub: my database IS accessible. cPanel is great. My host says the database is perfect and that a they could load in a backup from last night.

First, I had them load the backup wp-config (just in case), but that didn’t help. Then, they loaded the whole backup. Nothing.

If the DB is fine, wp-config hasn’t changed, htaccess hasn’t changed…what else could be going on?

Pulling out what hair I have left…