code: public synchronized void refreshNamespaces() {
  		/*
  		 * cache namespaces
  		 */
  		if (this.namespaceCache == null) {
  			this.namespaceCache = new TreeMap<String, Namespace>();
  			Node[] nodes = client.getNodes();
  			for (Node node : nodes) {
  				try {
  					String namespaceString = Info.request(getInfoPolicy(), node, "namespaces");
  					if (!namespaceString.isEmpty()) {
  						String[] namespaceList = namespaceString.split(";");
  						for (String namespace : namespaceList) {
  							Namespace ns = this.namespaceCache.get(namespace);
  							if (ns == null) {
  								ns = new Namespace(namespace);
  								this.namespaceCache.put(namespace, ns);
  							}
  							refreshNamespaceData(node, ns);
  						}
  					}
  				} catch (AerospikeException e) {
  					log.error("Error geting Namespaces ", e);
  				}
  
  			}
  		}
  	}
docs: refreshes the cached Namespace information