Enable ZLIB for streaming ingest

Per gopalv's recommendation tried running streaming ingest with and without zlib. Following are the numbers

 
Compression: NONE
Total rows committed: 93800000
Throughput: 1563333 rows/second
$ hdfs dfs -du -s -h /apps/hive/warehouse/prasanth.db/culvert
14.1 G  /apps/hive/warehouse/prasanth.db/culvert
 
Compression: ZLIB
Total rows committed: 92100000
Throughput: 1535000 rows/second
$ hdfs dfs -du -s -h /apps/hive/warehouse/prasanth.db/culvert
7.4 G  /apps/hive/warehouse/prasanth.db/culvert
 
ZLIB is getting us 2x compression and only 2% lesser throughput. We should enable ZLIB by default for streaming ingest.