From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Zhuravlev Date: Mon, 22 Sep 2008 11:05:54 +0400 Subject: [Lustre-devel] Doubly indexed tree / changelogs In-Reply-To: References: Message-ID: <48D743D2.6010201@sun.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org IMHO, it'd be useful to insert aggregations into that index. just to keep the index small. say, subtree? thanks, Alex Peter Braam wrote: > Objects can be in many filesets, and be added to some, removed from others. > > I think this is an almost arbitrary collection of pairs (FID, fileset-id) > and we need it indexed by both. > > Peter > > > On 9/22/08 1:52 PM, "Alex Zhuravlev" wrote: > >> can object migrate between filesets? if not, we probably >> can use fid's sequence as a record in that index? >> >> thanks, Alex >> >> Peter Braam wrote: >>> Hi Nikita, Nathan - >>> >>> After some pondering I have come to two conclusions. >>> >>> To encode filesets, we need a tree that makes two iterations fast: >>> >>> 1. list all filesets that contain a certain object >>> 2. list all objects in a certain fileset >>> >>> >>> Is there a doubly indexed tree for this? >>> >>> Secondly, to make the changelogs useful and scalable for filesets we >>> will need to be able to list all changelog entries associated with a >>> certain inode efficiently. I see two ways to do this ? one is an >>> auxiliary directory file mapping inodes to many changelog entries, the >>> second is to embed forward and backward pointers in the changelog >>> entries to build a linked list rooted at the inode (using an EA in the >>> inode pointing to the first and last element of the list). Both have >>> some overheads. What are your thoughts? >>> >>> Peter >>> >>> >>> ------------------------------------------------------------------------ >>> >>> _______________________________________________ >>> Lustre-devel mailing list >>> Lustre-devel at lists.lustre.org >>> http://lists.lustre.org/mailman/listinfo/lustre-devel > >