Hi Schubert, Please address Cloudera-specific issues to the cdh-user list. I see you've also sent this there - I'll get back to you on that thread.
Thanks, Todd On Wed, Oct 20, 2010 at 8:05 AM, Schubert Zhang <zson...@gmail.com> wrote: > Hi Cloudera, > > In my test, I found a following issue about HDFS sync(). > > Note:in my test, i just set the block size=16MB, since I use a VMware > workstation in my PC. > > (1). I create a new file in HDFS and write some bytes (the size of these > bytes > one block). > (2). Then I call the sync() method of FSDataOutputStream, and check the > data > in DataNode, there are two block for this file. It's right. > > [r...@localhost hadoop-test]# ls ~/data/hadoop-root/dfs/data/current/ -l > total 16544 > -rw-r--r-- 1 root root 16777216 Oct 20 19:56 blk_8183064348066912658 > -rw-r--r-- 1 root root 131079 Oct 20 19:56 > blk_8183064348066912658_1001.meta > -rw-r--r-- 1 root root 0 Oct 20 19:54 > dncp_block_verification.log.curr > -rw-r--r-- 1 root root 154 Oct 20 19:54 VERSION > [r...@localhost hadoop-test]# ls > ~/data/hadoop-root/dfs/data/blocksBeingWritten/ -l > total 14116 > -rw-r--r-- 1 root root 14311674 Oct 20 19:56 blk_-6758853111108478244 > -rw-r--r-- 1 root root 111819 Oct 20 19:56 > blk_-6758853111108478244_1001.meta > > (3) But when I get the FileStatus of this file, the length is only > 16777216, > and only one block returned by fs.getFileBlockLocations(...) > > path = hdfs://localhost:9000/testfile > length = 16777216 > blockSize = 16777216 > replication = 1 > mTime = 1287575815844 > aTime = 1287575815844 > permission = rw-r--r-- > owner = root > group = supergroup > ---------Blocks-------- > 0,16777216,localhost.localdomain > > I think it may be a bug here. > > (4) Then, I try to seek to a position >16777216 and < (16777216+14311674), > and try to read something. > the seek() and read() operations are both ok. > > Schubert > -- Todd Lipcon Software Engineer, Cloudera
