We intend to use the Spread toolkit (www.spread.org) for communication among the replicas. Key features of Spread that make it attractive for this project are:
- high performance group communication
- range of services from reliable messages to causally and totally ordered communications (CATOCS)
- available under an Open Source license
It's not clear exactly what "high performance" means, but we expect that performance is good enough for the anticipated needs of Zope storages.