Every so often I find myself looking at executor logs, wondering why something is going wrong (failed exec, or seems to be stuck etc) and I wish I had a bit more info about shuffle sizes. ShuffleBlockFetcherIterator logs the number of local & remote blocks, but not their sizes. It would be really easy to add in size info too.
eg. instead of
it should be
I know this is a really minor change, but I've wanted it multiple times, seems worth it.