Thrown when a paritioned region is configured for disk persistence,
and part of the data is stored on members that are known to be offline.
With a partitioned region, the keyspace is segmented into buckets which are
assigned to individual members. If all members that are storing data
for a particular bucket are offline, any attempt to access or update
data in that bucket will throw this exception.
If you see this exception, that means that you need to restart the
members that host the missing data.
If you receive this exception when attempting an operation that modifies
the region (such as a put), it is possible that the change was actually
persisted to disk before the member went offline.