Jimmy Wales wrote:
Hybrid approaches are possible -- the webservers could NFS mount the
/images/ directory from the db machine but only use the NFS
mountpoints for writing -- for reads, we'd go through the reverse
proxying mechanism.
--Jimbo
Why not keep the master copies NFS mounted on the database machines,
_and_ local copies cached on the web server filesystems?
The same caching algorithm can be used for image files and rendered
pages, except that the "rendering" process for image files is a simple
copy from the master NFS server if the DB timestamp is more recent than
the local file timestamp. In this way, no web serving would need to
occur directly from the master.
In addition, running rsync periodically on the slaves to sync their
image directories with those of the master would have the effect of
keeping local copies up-to-date with very low overhead, and without
disturbing the caching algorithm described above.
This would also make switching to "disconnected mode" easy, if the
central DB / NFS server goes down.
-- Neil