Changes between Initial Version and Version 10 of Ticket #935


Ignore:
Timestamp:
2019-09-08T22:39:58Z (5 years ago)
Author:
amontero
Comment:

Legend:

Unmodified
Added
Removed
Modified

  • Ticket #935

    • Property Keywords fuse smb sftp sshfs webdav cache preservation gsoc added
    • Property Cc amontero@… added
    • Property Milestone changed from undecided to eventually

  • Ticket #935 – Description

    initial v10  
    11At lunch today, Zandr and I were talking about an interesting approach to a
    22tahoe frontend.
    3 
    43Imagine, if you will, a NAS box, to which your client connects via webdav or
    54some other convenient protocol. On this box sites a specialized webdav
    65server, a Tahoe node, and a bunch of (real) disk.
    7 
    86The server maintains a database. For each pathname visible to the client, the
    97database records two things: "file present on disk?" and "filecap in grid?".
    … …  
    1412disk, then (in the background) fills the rest of the local disk file with
    1513data from the grid.
    16 
    1714On write, the server writes data to a real local file. Later, when the file
    1815has stopped twitching, the server uploads the file into the grid and updates
    1916the database to reflect the filecap.
    20 
    2117Much later, when the server concludes that this file is no longer "hot", it
    2218removes the local disk copy. There are two separate timers: one to decide
    … …  
    2420interesting enough to spend local disk space on. The latter timer is likely
    2521to be related to the amount of disk space available.
    26 
    2722From the client's point of view, this is just a NAS box that occasionally
    2823suffers from higher-than-normal latency, but all of its contents eventually
    2924show up on a tahoe backup grid.
    30 
    3125Shared directories must be tolerated somehow. I imagine that the server
    3226maintains a cache of dirnode contents (so that the client sees directories
    … …  
    3731version, the new local version, and the new upstream version, and let the
    3832user sort it out.
    39 
    4033This idea has been partially explored before, both by the windows FUSE-like code that
    4134shipped with the allmydata.com client, and in the OS-X FUSE code