We are currently having Sitecore 9.0 Update 2 which runs on Azure on PAAS. We are planning to implement Blue/Green deployment for zero downtime The plan is to have 2 set environments as Blue will have 1CM, 2 CDs (active) and Green will have 1CM, 2 CDs (standby).
My question is has anyone has implemented this type of set up before? How could you keep two Web databases(Blue & Green) in sync with this kind of approach