Hi Colin, Thanks for your reply. What is mean that the patch will work on files that are in the process of being written?
Thanks, LiuLei 2012/10/1 Colin McCabe <cmcc...@alumni.cmu.edu> > I'm going to post a patch to HDFS-347 shortly. From the user's point > of view, the important thing about the new implementation of local > reads is that it will work with security, and will work on files that > are in the process of being written. > > cheers, > Colin > > > On Thu, Sep 27, 2012 at 9:30 PM, jlei liu <liulei...@gmail.com> wrote: > > Hi Colin， thanks for your reply. > > > > Where can I see the new design for BlockReaderLocal class? > > > > Thanks, > > > > LiuLei > > > > > > > > 2012/9/28 Colin McCabe <cmcc...@alumni.cmu.edu> > >> > >> We don't make very strong guarantees about what happens when clients > >> read from a deleted file. DFSClients definitely may read data from a > >> deleted file even if local reads are not enabled. > >> > >> Incidentally, BlockReaderLocal is being redesigned to pass file > >> descriptors rather than paths, which will be more secure and fix some > >> corner cases surrounding append and local reads. > >> > >> cheers, > >> Colin > >> > >> > >> On Wed, Sep 26, 2012 at 11:19 PM, jlei liu <liulei...@gmail.com> wrote: > >> > In local read, BlockReaderLocal class use "static Map<Integer, > >> > LocalDatanodeInfo> localDatanodeInfoMap" property to store local block > >> > file > >> > path and local meta file path. When I stop HDFS cluster or I kill the > >> > local > >> > DataNode and delete file use "./hadoop dfs -rm path" command , the > >> > DFSClient > >> > still can read the data form local file. I think that may lead to > >> > DFSClient > >> > read wrong data. > >> > > >> > I think we should fix the problem. > >> > > >> > > >> > Thanks, > >> > > >> > LiuLei > > > > >
