DistributedCache replication

[warjort]

I'm trying to create an alternate to the infinispan replicated cache that has 2 key properties that don't seem to be compatible with the current DistributedCache api.

1) The version/metadata/timestamp/attributes are stored in a blob together unlike the infinispan cache where they are stored seperately - but automatically using the AtomicMap.

2) The data is stored remotely so retrieving data that I am not told to replicate so as to recreate the full blob is expensive.

The issue comes from the following code in SessionBasedClusteredSession

    @Override
    protected OutgoingSessionGranularitySessionData getOutgoingSessionData() {
        Map<String, Object> attrs = isSessionAttributeMapDirty() ? getSessionAttributeMap() : null;
        DistributableSessionMetadata metadata = isSessionMetadataDirty() ? getSessionMetadata() : null;
        Long timestamp = attrs != null || metadata != null || getMustReplicateTimestamp() ? Long.valueOf(getSessionTimestamp())
                : null;
        return new OutgoingData(getRealId(), getVersion(), timestamp, metadata, attrs);
    }

Where the DistributedCache is not told all the data on subsequent replication requests if has not changed.

I'd like to have either;

1) Some way to tell it to always give me all the data - this data is held in the local cache

2) Some way of getting access to the local data so I can retrieve the data that hasn't changed without going to my remote store

[warjort]

Incidently, I think the following code is wrong in the infinispan implementation of DistributedCacheManager

@Override

public void storeSessionData(final T sessionData) {
    
final K key = this.keyFactory.createKey(sessionData.getRealId());


    
trace("storeSessionData(%s)", key.getSessionId());


    
Operation<Void> operation = new Operation<Void>() {
        
@Override
        
public Void invoke(Cache<K, Map<Object, Object>> cache) {
            
Map<Object, Object> map = cache.putIfAbsent(key, null);


            
SessionMapEntry.VERSION.put(map, Integer.valueOf(sessionData.getVersion()));
            
SessionMapEntry.METADATA.put(map, sessionData.getMetadata());
            
SessionMapEntry.TIMESTAMP.put(map, sessionData.getTimestamp());
            
try {
                
DistributedCacheManager.this.attributeStorage.store(map, sessionData);
            
} catch (IOException e) {
                
throw getRuntimeException("Failed to store session attributes for session: " + mask(key.getSessionId()), e);
            
}
            
return null;
        
}
    
};


    
this.batch(operation);

}

In that it will overwrite thinks like the metadata with null if it hasn't changed.

see isSessionMetaDataDirty() referenced in the code above.