Wassim Drira wrote: > Hi all, > I am using tahoe v1.7 . I use SFTP interface to communicate with one client. > The remark was that after pushing huge amount of files in a directory, this > operation becomes very low after some days of use. It began with 0.3s to > become around 10s.
This is likely to be due to inefficiencies with large mutable files, which are used to implement directories (see http://tahoe-lafs.org/trac/tahoe-lafs/ticket/383 and http://tahoe-lafs.org/trac/tahoe-lafs/ticket/327). To confirm this and to eliminate any problem specific to the SFTP frontend, please try adding a file to the same directory via the web interface. This should also take 10 seconds. When using the SFTP interface, it is not possible to add multiple files to a directory at once, since the SFTP protocol doesn't have any way to express that. (I suppose it would be possible to batch requests, but that would probably have to be done as part of more general caching for mutable files.) If you can use the 'set_children' webapi request, rather than SFTP (see docs/frontends/webapi.txt), then that does allow adding multiple child entries at once. This would not change the time taken by each request (operating on a directory of a given size), but you might be able to use fewer requests. > Do you have a solution to this issue? Not immediately. The new "MDMF" format for mutable files that is planned to be added in 1.9.0 *may* help us to implement additions to mutable directories more efficiently, but without additional caching, I think it would still be necessary to read the whole directory on each request. -- David-Sarah Hopwood ⚥ http://davidsarah.livejournal.com
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