> We use Glue extensively, but we have a rule of thumb not to use any of the 'special sauce'. That means is using it purely for 'Spark as a service'
This is spot on IMO. I use Glue internally (opinions are my own) and still believe that the best course of action is Glue should only run managed Spark. We provide an empty Scala "script" that does nothing, and load a compiled JAR file with the Scala code that actually runs our job as a library and have Glue exec into that.
We can version the ETL in git, run local tests outside of the Glue data plane, prototype in the Spark shell, and much more.
By looking at the prices of a few fiction books in my collection over the period 2011-today I didn't see any evidence of the increasing price trend hinted at by the article.
The tech books I looked at might do, certainly a larger sample size would be interesting:
Tokens beginning with a colon are literal Ruby symbols.
Prepending an ampersand before the last argument of a method call means that argument should be converted into a Proc and sent as a callback block to that method.
Actually, it's &(:+) not &:(+). The & takes its argument and converts from a Proc to a block. :+ is a symbol that implements the method #to_proc to give you a block that sums its receiver and its argument.
