With 4.0 community edition there is no restriction for using CE (community edition) in production.
CE does not limit node count. However EE comes with additional scale and performance capabilities that will ensure it takes better advantage of the HW you throw at it.
You can switch to EE (enterprise edition) at any point with a simple swap rebalance.
thanks
-cihan
There is also concurrency limitations in the case of homogeneous scale-out (figure 1). Service limit their CPU utilization to ensure they don’t step on each this requests are queued and are not executed under N1QL when concurrency goes above 4 cores in Query Service.