O BigCouch 0,4 introduz um recurso de "zonas" que pode atender aos seus requisitos:
... the killer addition to BigCouch 0.4 is support for ‘zones,’ which allows you control over where you place the individual copies of your data. Cloudant’s hosted service makes extensive use of this feature to protect against isolated failures in individual data centers. As an example, our west coast cluster “Meritage” is actually spread over two different data centers in two distinct geographic regions. We use zone-support to ensure that at least one copy of all of our customers’ data exists in both locations. That way, if one location falls into the ocean or is subject to nuclear attack, our customers’ data is still safe and available. With this feature now in BigCouch, you can extend clusters across multiple locations. -- http://blog.cloudant.com/bigcouch-zero-point-four/