I have also doubt over WAL(write ahead log). In hdfs we can write a new file or we can append to old file.
Is that correct : 1. WAL only logs operations not its data... just like disk journaling(ext4) 2. In case of Region Server failure... WAL replay will depends on Client to get each operation's data that yet not committed/flushed to hdfs. 3. Hbase uses append operation in hdfs to store/log WAL. Thanks...
