Class MergePolicy.UnsupportedMergePolicy

    • Constructor Detail

      • UnsupportedMergePolicy

        public UnsupportedMergePolicy()
    • Method Detail

      • merge

        public CacheEntry merge​(CacheEntry preferredEntry,
                                List otherEntries)
        Description copied from interface: EntryMergePolicy
        This method is called by ConflictManager.resolveConflicts() for each conflict discovered to determine which CacheEntry should be utilised. This merge policy is used when a user explicitly calls ConflictManager.resolveConflicts() as well as when a partition merge occurs with PartitionHandling.ALLOW_READ_WRITES set. In the event of a partition merge, we define the preferred partition as the partition whom's coordinator is coordinating the current merge.
        Specified by:
        merge in interface EntryMergePolicy
        Parameters:
        preferredEntry - During a partition merge, the preferredEntry is the primary replica of a CacheEntry stored in the partition that contains the most nodes or if partitions are equal the one with the largest topologyId. In the event of overlapping partitions, i.e. a node A is present in the topology of both partitions {A}, {A,B,C}, we pick {A} as the preferred partition as it will have the higher topologId because the other partition's topology is behind. During a non-merge call to ConflictManager.resolveConflicts(), the preferredEntry is simply the primary owner of an entry
        otherEntries - a List of all other CacheEntry associated with a given Key.
        Returns:
        the winning CacheEntry to be utilised across the cluster, or null if all entries for a key should be removed.