The GemStone transaction docs describe a scheme that would work properly on a single machine, but don't discuss anything about distributed coordination across servers or failure modes. The installation instructions don't discuss setting up a cluster. The marketing docs discuss using thousands of VMs (clients) and scaling the dataset to "hundreds of gigabytes" based on disk storage instead of memory which is not what I would expect from a distributed system. Various benchmarks and user comments refer to using a single server for GemStone.

I will update the post to clarify that we are discussing distributed document databases only. It's easy to do anything you want on a single machine.