This is the best anti war base design I've used so far with the town hall level 9 account I'm using. I'll be sticking to this for the mean time. Though I haven't experienced yet being attacked by dragons. But most of my attackers , if not using giants and wizard, is using war hogs so I guess this would be the most practical design as of the moment.
You can also use this as a TH 9 farming base, just move the townhall outside the walls I and replace it with a storage or a piece of wall just to cover the hole in the middle.