Using Scala in Amazon Lambda for Processing Fastly Logs

"For java, there is absolutely some “jvm warmup” time that was noticed when there was low activity on the lambda function. To avoid this, we increased the frequency which Fastly was pushing S3 logs and we saw a 2x decrease in run time (from about 6 seconds to 3 seconds). "

Huh? Faster because AWS Lambda is now pre-warming JVMs, or just because it is keeping more of the said lambda function extracted from the zip file into the cache?

> Firstly, only Java 8 is supported, so your build.sbt needs > to have some configuration in it that enables 1.8 only > support

NONONONONONONONONO ! Who told you that? If you don't compile on Jdk 9 with target/source 9 it just doesn't matter which JVM version you use they should be Downwards Compatible, especially OpenJDK 8 which actually Lambda uses.