Package org.ehcache.spi.resilience

Interface ResilienceStrategy<K,​V>

  • Type Parameters:
    K - the type of the keys used to access data within the cache
    V - the type of the values held within the cache
    public interface ResilienceStrategy<K,​V>
    A strategy for providing cache resilience in the face of failure.

    An implementation of this interface is used by a cache to decide how to recover after internal components of the cache fail. Implementations of these methods are expected to take suitable recovery steps. They can then choose between allowing the operation to terminate successfully, or throw an exception which will be propagated to the thread calling in to the cache.

    Resilience in this context refers only to resilience against cache failures and not to resilience against failures of any underlying CacheLoaderWriter. To this end writer or loader failures will only be reported to the strategy in the context of a coincident cache failure. Isolated writer and loader exceptions will be thrown directly.

    • Method Detail

      • getFailure

        V getFailure​(K key,
             StoreAccessException e)
        Called when a Cache.get(java.lang.Object) fails on a cache without a cache loader due to an underlying store failure.
        Parameters:
        key - the key being retrieved
        e - the triggered failure
        Returns:
        the value to return from the operation

      • containsKeyFailure

        boolean containsKeyFailure​(K key,
                           StoreAccessException e)
        Called when a Cache.containsKey(java.lang.Object) fails due to an underlying store failure, and the resultant cache load operation also fails.
        Parameters:
        key - the key being queried
        e - the triggered failure
        Returns:
        the value to return from the operation

      • clearFailure

        void clearFailure​(StoreAccessException e)
        Called when a Cache.clear() fails due to an underlying store failure.
        Parameters:
        e - the triggered failure

      • iteratorFailure

        Cache.Entry<K,​V> iteratorFailure​(StoreAccessException e)
        Called when a cache iterator advancement fails due to an underlying store failure.
        Parameters:
        e - the triggered failure
        Returns:
        an entry to return on a failed iteration

      • putIfAbsentFailure

        V putIfAbsentFailure​(K key,
                     V value,
                     StoreAccessException e)
        Called when a Cache.putIfAbsent(java.lang.Object, java.lang.Object) fails due to an underlying store failure.

        If it is known at the time of calling that the key is absent from the cache (and the writer if one is present) then knownToBeAbsent will be true.

        Parameters:
        key - the key being put
        value - the value being put
        e - the triggered failure
        Returns:
        the value to return from the operation

      • removeFailure

        boolean removeFailure​(K key,
                      V value,
                      StoreAccessException e)
        Called when a Cache.remove(Object, Object) fails due to an underlying store failure.
        Parameters:
        key - the key being removed
        value - the value being removed
        e - the triggered failure
        Returns:
        the value to return from the operation

      • getAllFailure

        java.util.Map<K,​V> getAllFailure​(java.lang.Iterable<? extends K> keys,
                                       StoreAccessException e)
        Called when a Cache.getAll(java.util.Set) fails on a cache without a cache loader due to an underlying store failure.
        Parameters:
        keys - the keys being retrieved
        e - the triggered failure
        Returns:
        the value to return from the operation

      • putAllFailure

        void putAllFailure​(java.util.Map<? extends K,​? extends V> entries,
                   StoreAccessException e)
        Called when a Cache.putAll(java.util.Map) fails due to an underlying store failure.
        Parameters:
        entries - the entries being put
        e - the triggered failure

      • removeAllFailure

        void removeAllFailure​(java.lang.Iterable<? extends K> keys,
                      StoreAccessException e)
        Called when a Cache.removeAll(java.util.Set) fails due to an underlying store failure.
        Parameters:
        keys - the keys being removed
        e - the triggered failure