The amount of memory required by Confluence export a full backup seems to increase linearly as the size of the DB increases. At the moment if our instances' memory allocation is less than 512MB, the daily backup silently fails. The allocation during the backup goes quite close to the 512MB mark so seems I'll shortly have to increase the sizes even higher.

This isn't a problem right now (for us at least) but the backup should be refactored to "stream" the content into XML sooner or later as the current model will cease to work due to too large RAM requirements.

Other than the backup, the amount of RAM required by Confluence for "daily operations" seems nice and low.