Yes, it starts working after we restart the database, but we are still figuring out as to why this is happening again and again for the past 4 days. We atleast narrowed down the problem source.. Its Google!
We have found a resolution to the site downtime issue and we have put a fix in place. Google should now be able to spider our site without bringing it down. The fix is in place for the past 3 days and we wanted to wait to make sure it works before we announce it. All is well now. Thank you.