Our web apps (30 or so) log application specific stuff to a centralized logging database (Sql Server 2012) with log4net, so the logging database gets huge quickly. Thus we decided to replace it every year, like renaming the current logging database (eg. AppLog to AppLog2015) then creating a new logging database (AppLog) for the web apps. We need to keep the replaced databases for a future inquiry.
What is the best practice to do these replacing things? Is it better to simply set some downtime all the apps while replacing? Or is it possible to replace the database without some downtime?
Any advice would be appreciated. Even totally different approach advice is also welcome.