Who holds the pen
The room splits and half the clerks can no longer see the pen. How many pens are there now?
Five clerks share one pen, and only the clerk holding it may write in the book. The night's writes land wherever a desk is nearest, and the middle panel shows each side of the room and the book it is keeping. Watch the bill count lines written while two pens were out.
Board: Who Holds the Pen →Fourteen fixed writes across five clerks. Step through them yourself. Nothing plays automatically.
try this Stay on Whoever asks first, press Add next write to the end of the night, and watch The bill so far.
Included with a plan
This lab is included with a plan. The first three lessons of every track are free, with their boards and videos. A plan unlocks every lesson, board, video, lab and paper for one price.
see also In Search of an Understandable Consensus Algorithm, The Google File System, Spanner: Google's Globally-Distributed Database, Time, Clocks, and the Ordering of Events in a Distributed System, Paxos Made Simple, The Chubby lock service for loosely-coupled distributed systems and ZooKeeper: Wait-free coordination for Internet-scale systems in Papers.