On 2/2/22 13:55, Chuck Lever III wrote:
On Feb 1, 2022, at 8:41 PM, Simon Kirby <sim@xxxxxxxxxx> wrote:
How far off would we be from write delegations happening here?
We are tracking a "feature request" for write delegation support
in the Linux NFS server:
https://bugzilla.linux-nfs.org/show_bug.cgi?id=348
At this point the effort is not resourced. It's not clear how
much benefit it would be.
First shock is I thought write delegation was already supported.
But especially for users who have NFS mounted home directories, how
could there not be a major performance benefit? To cite one example that
has been a problem before (in particular, on Mac OSX clients with NFSv3
home directories mounted from a linux fileserver), facilitating the
firefox "awesome" bar, which writes to a SQLlite database in
~/.mozilla/fireworks with alarming frequency in order to keep up the
awesomeness.
This flat out didn't work previously unless you went to about:config and
set
storage.nfs_filesystem = true
Not at all sure how this changed the execution of firefox though.
That said, it seems to me that your use case might benefit if
the Linux NFS server offered a READ delegation for the SQLite
database file even when it is open R/W. It might be appropriate
if the server offered such a delegation when there are no other
clients that have the file open for write or that hold write
delegations.
Patches and performance data are, as always, welcome.
--
Chuck Lever
