快速的數據操作框架：Hydro

Hydro是一個免費和開源的數據 API 計算和服務框架，設計幫助 Web/應用服務器和其他數據消費者從不同的數據流中抽取數據，并快速處理。然后基于標準和統計數據呈現給不同的客戶端/應用程序。

|-------|
           |  DB1  |======
           |-------|     =
               .         =      Data API           
                         =    |-----------|        
               .         = >  | HYDRO -   |        |---------|        
                         =    | Extract   |        | APP/Web |        |--------|
===ETL===>     .         =    | Transform | =====> | Server  | =====> | Client |     
                         = >  | Render    |        |---------|        |--------|
               .         =    |-----------|                       
                         =                         
           |-------|     =
           |  DBn  |====== 
           |-------|

#creating a plan object
plan = PlanObject(params, source_id, conf)
# defining data source and type
plan.data_source = 'vertica-dash'
plan.source_type = Configurator.VERTICA

# time diff based on input params
time_diff = (plan.TO_DATE - plan.FROM_DATE).total_seconds()

# if time range is bigger than 125 days and application type is dashboard, abort!
# since data need to be fetched quickly
if time_diff > Configurator.SECONDS_IN_DAY*125 and params['APP_TYPE'].to_string() == 'Dashboard':
raise HydroException('Time range is too big')

# else, if average records per day is bigger than 1000 or client is convertro then run sample logic
elif plan.AVG_RECORDS_PER_DAY > 1000 or params['CLIENT_ID'].to_string() == 'convertro':
plan.template_file = 'device_grid_widget_sampling.sql'
plan.sampling = True
self.logger.debug('Sampling for the query has been turn on')

# else run other logic
else:
plan.template_file = 'device_grid_widget.sql'
#return plan object to the query engine
return plan

項目主頁：http://www.baiduhome.net/lib/view/home/1425536250322