As this thread likely has attracted some 'IT people', a question.
Is it not possible, or practical to have a 'twin' website/system functioning in every respect but live (and probably based on a 'server' (layman's term) far removed from the 'regular' one). In which case it could:
* Take over after some necessary short period if the main 'server' should go down, or be compromised; and/or
* Take over while the main server website is being maintained/upgraded, allowing the main one to be updated in a non-urgent fashion, and be tested etc?
* When the main is updated, tested and stable, switch it live and after a day or so of functionality, copy it over to the reserve.
... especially for businesses were their main business revenue is generated from their web site?