vBulletin database accessed by two servers at a time: concurrency?
 

Our website www.msweb.nl, including our vB forum, is going to be transferred to a new hosting provider.

However: the propagation of the update of DNS all over the internet appears to take some 24 hours. We don't want our forum to close for updates for that time. Therefore we are planning to move our forum database a few days beforehand, and pointing to one database from two webservers: the old AND the new provider.

My question is about concurrency:
I'm a bit concerned about people posting or registering from two different web servers, during this 24 hours: For example: are the forum post counts updated consistently? And the different tables with userid as a key?