I use hadoop-0.20.2-cdh3u5 version, and config dfs.client.read.shortcircuit=ture.
I use 10 threas to pread local file, the file is 700m and the OS cache the file. When I config the dfs.client.read.shortcircuit.skip.checksum=false, the TPS is about 2000. When I config the dfs.client.read.shortcircuit.skip.checksum=true, the TPS is about 17000. Why when don't read meta file, the performance improve 8 times? If the reason is there are two times seek, I think whether we should save the checksums to block file. Thanks, LiuLei
