As of about 5:30am last night (this morning?) Grooveshark is now using MongoDB to house playlist information.
Until now playlists have lived in MySQL, but there were some big problems that occasionally lead to data loss due (mostly) to deadlocks. Needless to say, users don’t like it when you lose their data. Moving to Mongo should resolve all of these issues.
Grooveshark has been using MongoDB for sessions and feed data for a while now, so we are comfortable with the technology and know that it is capable of handling massive amounts of traffic. while it’s certainly not perfect, we are confident that it will be easy to scale out to maintain reliability as our user base continues to grow rapidly.