I'm looking at what it currently takes to implement new back end
filestores, getting lost in the details.
This is my current understanding -am I wrong?
1. There is an AbstractFileSystem, came in with HADOOP-6223, and is in
SVN_HEAD only
https://issues.apache.org/jira/browse/HADOOP-6223
2. There is FileSystem, which exists and includes methods like append()
3. There is not currently any generic stress test for a filesystem other
than terasort, but that doesn't really push the limit on FS operations,
concurrency issues, appends, etc.
4. There is not currently much in the way of subclasses of
AbstractFileSystem other than a bridge to the classic FileSystem
5. Because the AbstractFileSystem hasn't yet shipped, it offers the
opportunity to add things like progress callbacks (HADOOP-6324).
6. Because the AbstractFileSystem hasn't yet shipped, if you want people
on 0.20.x or 0.21.x to use your filesystem, you need to implement
FileSystem.
I'm curious as I need to know where to point some people. Short term,
FileSystem looks like the one to target, and because AFS wraps it, you
could stay with it for a while before worrying about AFS support
altogether...
-steve
