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 Summary

Modifier and Type	Method and Description
void	clearFailure(StoreAccessException e) Called when a Cache.clear() fails due to an underlying store failure.
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.
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.
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.
Cache.Entry<K,V>	iteratorFailure(StoreAccessException e) Called when a cache iterator advancement fails due to an underlying store failure.
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.
void	putFailure(K key, V value, StoreAccessException e) Called when a Cache.put(java.lang.Object, java.lang.Object) fails due to an underlying store failure.
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.
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.
void	removeFailure(K key, StoreAccessException e) Called when a Cache.remove(java.lang.Object) fails due to an underlying store failure.
boolean	removeFailure(K key, V value, StoreAccessException e) Called when a Cache.remove(Object, Object) fails due to an underlying store failure.
V	replaceFailure(K key, V value, StoreAccessException e) Called when a Cache.replace(java.lang.Object, java.lang.Object) fails due to an underlying store failure.
boolean	replaceFailure(K key, V value, V newValue, StoreAccessException e) Called when a Cache.replace(java.lang.Object, java.lang.Object, java.lang.Object) fails due to an underlying store failure.

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

putFailure

void putFailure(K key,
                V value,
                StoreAccessException e)

Called when a Cache.put(java.lang.Object, java.lang.Object) fails due to an underlying store failure.

Parameters:

key - the key being put

value - the value being put

e - the triggered failure

removeFailure

void removeFailure(K key,
                   StoreAccessException e)

Called when a Cache.remove(java.lang.Object) fails due to an underlying store failure.

Parameters:

key - the key being removed

e - the triggered failure

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

replaceFailure

V replaceFailure(K key,
                 V value,
                 StoreAccessException e)

Called when a Cache.replace(java.lang.Object, java.lang.Object) fails due to an underlying store failure.

Parameters:

key - the key being replaced

value - the value being replaced

e - the triggered failure

Returns:

the value to return from the operation

replaceFailure

boolean replaceFailure(K key,
                       V value,
                       V newValue,
                       StoreAccessException e)

Called when a Cache.replace(java.lang.Object, java.lang.Object, java.lang.Object) fails due to an underlying store failure.

Parameters:

key - the key being replaced

value - the expected value

newValue - the replacement value

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