That's a typical database connection overload. In a dynamic PHP site there are various means of redirection to different pages based on events, one being your login status for example. When an error message generated by the SQL server for whatever reason outputs text to the page the redirection cannot happen so you get the series of errors and finally some page half rendered in your browser. These are intermittent. Not much you can do about it. Just wait and try later when they restart the services.
