This doesn't seem right.  Looking at https://github.com/apache/hadoop-common/blob/trunk/hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/main/java/org/apache/hadoop/mapreduce/lib/input/FileSplit.java , this results in not populating hosts (and the write side doesn't write them) and not reading the "path" at the top of the split. So this will likely fail reading old parquet files? And even if it works, it will no longer populate hosts.

It seems like changing this behavior is unnecessary, and we can just cleanly override readFields/writeFields, without trying to reuse the parent behavior.