TAP client within spymemcached does not get all items from cluster

From the customer:

TapClient client = new TapClient(baseURIs, "default", "default", "");

Operation op = client.tapDump("test tap client");

while (client.hasMoreMessages()) {
ResponseMessage message = client.getNextMessage();
if (message != null)

{ System.out.println(message.getKey()); }

}

I made the client point to a cluster that has 60 M records . The client printed out about 8M and stopped without error, when I tried again it stopped at 10M.