This is actually a really good example of the CAP theorem. Because of the way Docs merges updates to a single document they had to either tie an editable docum

This is actually a really good example of the CAP theorem. Because of the way Docs merges updates to a single document they had to either tie an editable document to a single machine or risk inconsistent updates. The choice was made to ensure consistency. If a doc gets too popular to be served off a single machine then it goes into read-only mode and gets distributed to multiple boxes. When the traffic dies down it can fall back to a single box and re-enter read/write mode.