PHP Warning: SimpleDB::batchPutAttributes(): ServiceUnavailable: Service AmazonSimpleDB is currently unavailable. Please try again later in /var/www/****/SimpleDB/sdb.php on line 1021 Items FAILED ErrorCode: ServiceUnavailableHowever at about the time that twitter went offline, we noticed almost every other insert producing an error. When that happens we have coded our script to sleep a few seconds and retry the insert. The second attempt was completed successfully almost everytime. I went to tweet about it to find that twitter has gone offline. AFAIK, twitter has not publicly stated what their database platform is. They might do so at chirp so for the moment I am going to hazard a guess that they are using SimpleDB to store some of their data. All their static content is served out of Amazon S3 so this is not a wild guess (I hope). I am now going to leap to the conclusion that the two errors are related and make a fool of myself.