faster forumsI think I have perceived some speed increases on the forums in the last week as we have (on phpbb2 for now) moved smilies/ranks/gallery avatars off on to there own servers. This allows browsers to get more parallel requests in at a time and at the same time decreases load on the main boxes.
What I think is more exciting is the code is also ready now, to do much the same thing with template images.
Nightly a script will look at the templates and if you are not in the process of editing a template and a copy has not already been made, then the template will be copied (creating a backup) to yet another server, the template will then be marked a backed up and that its images should be served from the template server.
If the admin ever enters the template editor then the backup and redirect marks will be deleted. e.g. if you are developing a template then things will be absolutely the same as normal. Once you are finished then your forum will get the boost of an additional server.
Of course we won't quite get a 400% speed increase, but if a forum is now using 4 servers to deliver its content simultaneously, and the load is also less on the main box, then there should be quite a notable boost.
The one main thing left to do, is that whilst we can live with smilies or ranks or avatars being inaccessible with a server issue, we cannot live with template images not working.
If we do rely on 4 servers each with 99.9% uptime, then overall uptime becomes 99.6% to avoid this a polling system needs to be written that will check the 3 image servers every minute or two and stop the forums using them if they are down. Since all images will still be on the main servers this should be quite transparent.
A small but useful side effect of the new system is that templates will be getting nightly backups and can be removed from the main system backup.
This has one drawback in that if a rogue admin messes up a template, then there will be a more limited window for restoration But we cannot run the system around the need to deal with rogue admins.