Acker task doesn't collect ack_ack messages from bolts

[francesco . masucci]

Hello i am testing Storm on my local machine with the following 
configuration

Config conf = new Config();
                conf.put(Config.TOPOLOGY_RECEIVER_BUFFER_SIZE,8);
                conf.put(Config.TOPOLOGY_TRANSFER_BUFFER_SIZE,32);
                conf.put(Config.TOPOLOGY_EXECUTOR_RECEIVE_BUFFER_SIZE,16384);
                conf.put(Config.TOPOLOGY_EXECUTOR_SEND_BUFFER_SIZE,16384);
                conf.put(Config.TOPOLOGY_ACKER_EXECUTORS, 2);
                conf.put(Config.TOPOLOGY_WORKERS, 3);
                conf.registerSerialization(FacebookPost.class);
                conf.registerSerialization(TweetMessage.class);
                conf.setDebug(true);

all  the bolts and spouts of my topology execute just one task . What 
happens is that the akcer task don't collect ack_ack messages coming 
from the bolts of my topology , thus causing a lot of tuples to fail and 
be replaced even if they were already processed succesfully .
Is there a way to tweak the parameters of the topology so that the 
executor tasks gets executed more often to prevent a lot of tuples from 
failing ?

Regards

Francesco Maria Masucci