Comment by KirinDave

> Then at the very bottom of it all there's a big pile of MySQL instances. Plus some ugly JNI/C++ code allowing the Java parts to come in through a side door of the MySQL interface, bypassing most of the query optimizer (since none of the queries are complex) and hitting InnoDB almost directly.

Ah! I knew it! It's an orchestration layer on top of a mysql layer with floating masters.

I remember back when DDB was first launched we all sat around at Powerset and tried to figure out how Amazon did it given the two pieces of information we were given: "it is not based off the dynamo paper" and "it is based off both open source and proprietary code". We figured it had to be MySQL or Postgres that they were referring to.

I didn't know you were completely bypassing the query layer though.