code: public void initialize(Map<String, String> params) throws WPBIOException
  	{
  		try
  		{
  			memcacheClient = new WPBMemCacheClient();
  			String address = "";
  			if (params!= null && params.get(CONFIG_MEMCACHE_SERVERS) != null)
  			{
  				address = params.get(CONFIG_MEMCACHE_SERVERS);
  			}
  			memcacheClient.initialize(address);
  			
  			if (params.get(CONFIG_MEMCACHE_CHECK_INTERVAL) != null)
  			{
  				try
  				{
  					sleepTime = Integer.valueOf(params.get(CONFIG_MEMCACHE_CHECK_INTERVAL));
  				} catch (NumberFormatException e)
  				{
  					// do nothing, rely on default value
  				}
  			}
  			WPBMemCacheSyncRunnable syncRunnable = new WPBMemCacheSyncRunnable(this, memcacheClient, sleepTime);
  			(new Thread(syncRunnable)).start();
  			
  		} catch (IOException e)
  		{
  			throw new WPBIOException("cannot create memcache client", e);
  		}
  	}
docs: default sleep time is 10 seconds