Best Practice for Sync Between Primary and Failover

I am writing an auto-registration service that will allow machines to add themselves to the Load Balancer. Due to the transactional nature of this process, I am never quite sure when everyone is registered. If a synch call is blocking to the point where I would have wait 2-10 seconds for the synch to complete before the transaction could complete. It would render the service unusable perfomance wise. Is the sych call non-blocking? Can I run it on the through a cron job on the LB without adversley affecting performance?

 

 

Thanks in advance,

 

Justin