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.