Amazon's EC2 stands for Amazon Elastic Computing Cloud. It is a service provided by Amazon that allows web applications to scale quickly with demand. As more instances of the application are needed, they can be quickly created via interfaces provided by Amazon. Likewise, instances can be removed just as easily.

ElectroServer Enterprise works with Amazon's EC2. While ElectroServer 4 Pro can work with Amazon's EC2 it doesn't make much sense due to it only running in standalone mode. Scaling by spawning multiple standalone servers segregates the users so that they cannot see each other or interact across servers. Also, a server license is needed for each instance.

ElectroServer 4 Enterprise is more suited for the EC2 system. It scales by allowing for the addition of gateway servers to manage many thousands of clients a piece. Users connected to different gateways can still interact. The gateways can come online or be taken offline at run-time. As the demand grows and new instances are needed, they can simply be brought online via the Amazon interface. Any users that are currently connected to a gateway that needs to be shutdown are asked to shift to another gateway.

ElectroServer 4 Enterprise running in distributed mode.

ElectroServer 4 Enterprise maintains its server state on one registry server. The registry server cannot span across multiple hardware instances. As the system scales new gateways can be added, but eventually the registry server can become a bottleneck. Depending on what your application is doing and what hardware you have chosen, you can potentially stretch into the hundreds of thousands of simultaneous users before a limit is reached.

A special license file is needed to enable the server to run in this type of environment. As each server instance is added or removed, it is given dynamically allocated IP addresses. For a server product like ElectroServer whose licensing model is single-install and IP driven, alternative security measures must be taken to restrict abuse. With the special dynamic IP license ElectroServer will need to validate its install at start-up and occasionally at run-time by "dialing home" to an Electrotank validation server.