On Sun, Oct 18, 2009 at 01:42, Mohit Sindhwani <[email protected]> wrote: > > Hi Jacob, > > Thanks for the quick reply. > > Jacob Helwig wrote: >> A common approach used for something like this is to have a "current" >> symlink, and update it, whenever you have a newer file. >> >> Eg: >> $ touch some-file-v1 >> $ ln -s some-file-v1 current-version >> $ touch some-file-v2 >> $ ln -sf some-file-v2 current-version >> >> If you give people the URL to "current-version", and only update the >> symlink after you've created the new version, then they won't be >> downloading a file before it's completely written out to disk. >> > > This seems simple enough! Would this approach also work if someone was > already accessing the older file when we try to do the second set of steps: > > $ touch some-file-v2 > $ ln -sf some-file-v2 current-version > > > Can I update a symlink while someone is already reading a file? >
This shouldn't cause a problem, because the file was already opened using the old "real" file's information about where it is on disk. (Though this is pretty easy to confirm for whatever your particular setup is.) > >> We use the "store the files in the DB" approach for a few of our >> projects at $work, and that works pretty well for us. It's not really >> a waste, especially if you plan on having multiple "physical" >> webservers. > Actually, I do use this for one of our solutions. The only concern is > that you need many more Mongrels if your files are very large - since > sending the file from database locks up the Mongrel for a longer period > of time... with small files, it works quite well. > It should also be possible to have whatever is delegating to Mongrel directly serve up files that exist on disk already. Then you could save things from the DB to disk, and not tie up a Mongrel worker after the first hit. This makes your "always download the most recent version" trickier, though. -Jacob --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en -~----------~----~----~----~------~----~------~--~---
