com.hazelcast.cache

Interface CacheMergePolicy

All Superinterfaces:

Serializable

All Known Subinterfaces:

StorageTypeAwareCacheMergePolicy

All Known Implementing Classes:

HigherHitsCacheMergePolicy, LatestAccessCacheMergePolicy, PassThroughCacheMergePolicy, PutIfAbsentCacheMergePolicy

public interface CacheMergePolicy
extends Serializable

Policy for merging cache entries after a split-brain has been healed.

Passed CacheEntryView instances wrap the key and value as their original types with conversion to object from their storage types. If you don't need the original types of key and value, you should use StorageTypeAwareCacheMergePolicy which is a sub-type of this interface.

See Also:

HigherHitsCacheMergePolicy, LatestAccessCacheMergePolicy, PassThroughCacheMergePolicy, PutIfAbsentCacheMergePolicy

Method Summary

Modifier and Type	Method and Description
Object	merge(String cacheName, CacheEntryView mergingEntry, CacheEntryView existingEntry) Selects one of the merging and existing cache entries to be merged.

Method Detail

merge

Object merge(String cacheName,
             CacheEntryView mergingEntry,
             CacheEntryView existingEntry)

Selects one of the merging and existing cache entries to be merged.

Note that the existingEntry may be null if there is no entry with the same key in the destination cache. This happens, when the entry for that key was

• only created in the smaller sub-cluster during the split-brain
• removed in the larger sub-cluster during the split-brain

Parameters:

cacheName - name of the cache

mergingEntry - CacheEntryView instance that has the cache entry to be merged

existingEntry - CacheEntryView instance that has the existing cache entry or null if there is no existing cache entry

Returns:

the selected value for merging or null if the entry should be removed