DrDr2 is a network of message passing servers. - Monitor finds pushes and sends them to the scheduler - The scheduler receives pushes, prepares a tar ball, and sends jobs to the masters - Each master sends commands to its slave and confirms to the scheduler (so that it will receive more commands) - The slave receives commands and executes them on a test machine and sends the answer to the master - The master receives the answer and sends it to the analyzer - The analyzer records data for the renderer and informs the notifier - The renderer queries the database ---- DrDr2 uses the MongoDB database for storage DrDr2 is monitored using Monit