yea, ingress is free on the aws side, and egress is expensive. The other thing is with a large amount of data you hit weird performance issues. Say you want t

yea, ingress is free on the aws side, and egress is expensive. The other thing is with a large amount of data you hit weird performance issues. Say you want to copy all your files on s3. One typical way of doing this is s3distcp in emr/hadoop, so you get distributed copying. But generally listing is single threaded, and if you have billions of files your cluster spends a noticeable amount of time idle while the master is doing the listing operation. Also list api costs can add up. S3 inventory probably alleviates this, it didnt exist at the time. So ignoring 'BigData', how would you shift a mysql database out. its either take downtime or do streaming replication or something. Gotta keep consistency, not lose writes, etc. moving stateless code around is so much easier than dealing with data. theres basically zero straight monetary cost to the move, you just deploy it somewhere else.