From: Daira Hopwood Date: Tue, 19 May 2015 23:27:10 +0000 (+0100) Subject: remote-to-local-sync.rst: Evaluation of designs section X-Git-Url: https://git.rkrishnan.org/simplejson/quickstart.html?a=commitdiff_plain;h=af95d968b3a6a7e2292cf4cae36533a29ca594d0;p=tahoe-lafs%2Ftahoe-lafs.git remote-to-local-sync.rst: Evaluation of designs section Signed-off-by: Daira Hopwood --- diff --git a/docs/proposed/magic-folder/remote-to-local-sync.rst b/docs/proposed/magic-folder/remote-to-local-sync.rst index a3ebab5f..859dc532 100644 --- a/docs/proposed/magic-folder/remote-to-local-sync.rst +++ b/docs/proposed/magic-folder/remote-to-local-sync.rst @@ -208,22 +208,34 @@ could not otherwise happen. application to Tahoe-LAFS requires significant design work, and may still leave some corner cases of the write coordination problem unsolved. -[Daira: -* designs 2 and 3 have no significant advantages over design 1, while + +*Evaluation of designs* + +Designs 2 and 3 have no significant advantages over design 1, while requiring higher polling bandwidth and greater complexity due to the need -to create subdirectories. They should be rejected. -* design 4 should be rejected due to the out-of-sync problem, which is -severe and possibly unsolvable for mutable structures. -* for design 5, the out-of-sync problem is still present but possibly +to create subdirectories. These designs were therefore rejected. + +Design 4 was rejected due to the out-of-sync problem, which is severe +and possibly unsolvable for mutable structures. + +For design 5, the out-of-sync problem is still present but possibly solvable. However, design 5 is substantially more complex, less efficient in bandwidth/latency, and less scalable in number of clients and subfolders than design 1. It only gains over design 1 on the ability to -share directory readcaps to the Magic Folder (or subfolders) which was -not a requirement, and IMHO could be better satisfied by design 6 in -future. -* design 6 is an unsolved design problem and should be considered out -of scope for the time being. We can benefit from experience with design 1 -when switching to design 6 later.] +share directory readcaps to the Magic Folder (or subfolders), which was +not a requirement. It would be possible to implement this feature in +future by switching to design 6. + +For the time being, however, design 6 was considered out-of-scope for +this project. + +Therefore, design 1 was chosen. That is: + +All subfolders written by a given Magic Folder client are collapsed +into a single client DMD, containing immutable files. The child name of +each file encodes the full subpath of that file relative to the Magic +Folder. + *Conflict detection*