What Happens When The Network Failure Is Fixed
Since it is a network failure, there is no way to programmatically avoid your application running as two separate independent clusters. But what will happen after the network failure is fixed and connectivity is restored between these two clusters? Will these two clusters merge into one again? If they do, how are the data conflicts resolved, because you might end up having two different values for the same key in the same map?
When the network is restored, all 271 partitions should exist in both mini-clusters and they should all undergo the merge. Once all primaries are merged,
all backups are rewritten so their versions are correct. You may want to write a merge policy using the MapMergePolicy interface that rebuilds the entry from the database rather than from memory.
The only metadata available for merge decisions are from the EntryView interface that includes object size (cost), hits count, last updated/stored dates, and a version number that starts at zero and is incremented for each entry update.
You could also create your own versioning scheme or capture a time series of deltas to reconstruct an entry.