Hi Stephen Watt, I am a fresh developer trying to add a NFS-like FileSystem support for Hadoop, and also have some confusion about the FileSystem Semantics.
Since I live in East Asia, I'd like to attend via Google Hangout if possible. Thanks. +1 Kun Ling yours, Kun Ling On Fri, May 24, 2013 at 7:52 AM, Stephen Watt <sw...@redhat.com> wrote: > Hi Folks > > Hadoop's pluggable filesystem architecture supports the ability to enable > an alternate filesystem for use with Hadoop by writing a plugin for it. We > now have several alternate filesystems that have Hadoop FileSystem plugins > and because this isn't a very well understood topic, I've been working on a > page on the project wiki to bring this all together - > http://wiki.apache.org/hadoop/HCFS. At the same time, the Ambari project > has been opening up Ambari to support any configured Hadoop FileSystem (as > opposed to just HDFS) over at > https://issues.apache.org/jira/browse/AMBARI-1817 > > My team (over at Red Hat) have been working on writing a Hadoop FileSystem > plugin for the glusterfs filesystem and have been finding that some of the > expected semantics of the operations within the Abstract FileSystem class > are a little ambiguous. With that said, we've joined Steve Loughran in > attempting to clarify these for both the Hadoop 1.0 and the Hadoop 2.0 > FileSystem class over at https://issues.apache.org/jira/browse/HADOOP-9371 > > It seems to me that once we had these semantics defined, it would be good > for consistency of implementation if we could make sure they are well > understood and properly implemented by the community of folks writing > Hadoop FileSystem plugins. To that end, we might work to ensure that those > semantics are tested within an exhaustive test framework that focuses on > the abstract Hadoop FileSystem layer. Each FileSystem provider could run > the tests to ensure their plugin implementation and behavior is consistent > with the expectation. Perhaps a broader extension of > https://issues.apache.org/jira/browse/HADOOP-9258. > > If folks are interested in these goals, I could host a > workshop/discussion/hackday in Mountain View to get local people together > (perhaps a Google Hangout for the remote folks) to keep the ball rolling on > the semantics discussion and test creation. As a side note, I think this > could also turn out be quite an effective means of introducing FileSystem > vendors to the ASF and getting them contributing to these aspects of the > project. > > Regards > Steve Watt > -- http://www.lingcc.com