Virtuoso Cluster supports optional fault tolerance by storing
partitions in more than one copy if desired. This is a cluster-only
feature, providing for transparent fail-over with fully
transactional semantics. This feature is in no way related to the
other forms of replication discussed in the Virtuoso documentation.
This feature can be used for load balancing of read-intensive
workloads and for fault tolerance of arbitrary workloads in a
tightly coupled cluster. This feature is not suited for
synchronizing geographically distributed copies.
Fault tolerance is enabled at the level of logical cluster.
Making the logical cluster __ALL fault tolerant has the effect of
making all the normally non fault tolerant database objects into
fault tolerant ones.