[OpenAFS] Re: Shared r/w access to numerous sqlite databases: an appropriate application for AFS?

Andrew Deason adeason@sinenomine.net
Thu, 8 Apr 2010 16:03:59 -0500

On Thu, 08 Apr 2010 16:43:55 -0400
Todd Lewis <utoddl@email.unc.edu> wrote:

> On 04/08/2010 04:06 PM, Brandon Simmons wrote:
> > For instance I envision a handful of clients on different machines
> > each writing to a single sqlite DB every few seconds; would this
> > defeat AFS's caching scheme?

As others have said, it'll be slow. But it should work; more likely to
work than NFS, anyway. Just don't turn off sqlite's fsync()ing behavior
(don't change the 'PRAGMA synchronous' setting from the default FULL).

In particular with the slowness, if one of those clients goes down that
was accessing the database, the next write could take many many seconds
to complete.

> arbitrate writes to maintain data integrity. AFS doesn't solve this
> problem (nor does NFS). Sorry.

I believe this would be a lot more efficient with XCB, if the written
sections are untouched by the other clients. It's not impossible for AFS
to do better.

Andrew Deason