Drupal or PHP would not connect to our MySQL database after database is restarted. The database was up and accepting connections, but Drupal or PHP would not make any connection attemps. It continued to report that the site was down because the database was down. I restarted Apache and it came back to life.

Is Drupal or PHP caching any database connections or tokens? If so, do you know how long the expiration for this was? I checked the site as much as 3 minutes past the database being back up, and it said down. That's which I restarted Apache.

If not caching, any idea why this would happen?

Drupal can be configured to cache. What are your cache settings like?

I've experienced similar mysterious inability to communicate with mysql. I got in the habit of restarting both.

Do you know which file these settings would be in? The setting name might help, too.