import time from datetime import datetime, timedelta import mysql.connector from sympy import sympify from multiprocessing import Pool import random import config ######################################################################################################################## # PROCEDURES: # Step 1: Query all virtual meters # Step 2: Create multiprocessing pool to call worker in parallel ######################################################################################################################## def calculate_hourly(logger): while True: # outer loop to reconnect server if there is a connection error cnx_system_db = None cursor_system_db = None try: cnx_system_db = mysql.connector.connect(**config.myems_system_db) cursor_system_db = cnx_system_db.cursor() except Exception as e: logger.error("Error in step 0 of virtual_meter.calculate_hourly " + str(e)) if cursor_system_db: cursor_system_db.close() if cnx_system_db: cnx_system_db.close() # sleep and continue the outer loop to reconnect the database time.sleep(60) continue print("Connected to MyEMS System Database") virtual_meter_list = list() try: cursor_system_db.execute(" SELECT id, name, equation " " FROM tbl_virtual_meters " " ORDER BY id ") rows_virtual_meters = cursor_system_db.fetchall() if rows_virtual_meters is None or len(rows_virtual_meters) == 0: # sleep several minutes and continue the outer loop to reconnect the database time.sleep(60) continue for row in rows_virtual_meters: meta_result = {"id": row[0], "name": row[1], "equation": row[2]} virtual_meter_list.append(meta_result) except Exception as e: logger.error("Error in step 1 of virtual meter calculate hourly " + str(e)) # sleep and continue the outer loop to reconnect the database time.sleep(60) continue finally: if cursor_system_db: cursor_system_db.close() if cnx_system_db: cnx_system_db.close() # shuffle the virtual meter list for randomly calculating the meter hourly value random.shuffle(virtual_meter_list) print("Got all virtual meters in MyEMS System Database") ################################################################################################################ # Step 2: Create multiprocessing pool to call worker in parallel ################################################################################################################ p = Pool(processes=config.pool_size) error_list = p.map(worker, virtual_meter_list) p.close() p.join() for error in error_list: if error is not None and len(error) > 0: logger.error(error) print("go to sleep ...") time.sleep(60) print("wake from sleep, and continue to work...") ######################################################################################################################## # Step 1: get start datetime and end datetime # Step 2: parse the expression and get all meters, virtual meters, offline meters associated with the expression # Step 3: query energy consumption values from table meter hourly, virtual meter hourly and offline meter hourly # Step 4: evaluate the equation with variables values from previous step and save to table virtual meter hourly # returns the error string for logging or returns None ######################################################################################################################## def worker(virtual_meter): cnx_energy_db = None cursor_energy_db = None try: cnx_energy_db = mysql.connector.connect(**config.myems_energy_db) cursor_energy_db = cnx_energy_db.cursor() except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 1.1 of virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" print("Start to process virtual meter: " + "'" + virtual_meter['name']+"'") #################################################################################################################### # step 1: get start datetime and end datetime # get latest timestamp from energy database in tbl_virtual_meter_hourly #################################################################################################################### try: query = (" SELECT MAX(start_datetime_utc) " " FROM tbl_virtual_meter_hourly " " WHERE virtual_meter_id = %s ") cursor_energy_db.execute(query, (virtual_meter['id'],)) row_datetime = cursor_energy_db.fetchone() except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 1.2 of virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" start_datetime_utc = datetime.strptime(config.start_datetime_utc, '%Y-%m-%d %H:%M:%S') start_datetime_utc = start_datetime_utc.replace(minute=0, second=0, microsecond=0, tzinfo=None) if row_datetime is not None and len(row_datetime) > 0 and isinstance(row_datetime[0], datetime): # replace second and microsecond with 0 # note: do not replace minute in case of calculating in half hourly start_datetime_utc = row_datetime[0].replace(second=0, microsecond=0, tzinfo=None) # start from the next time slot start_datetime_utc += timedelta(minutes=config.minutes_to_count) end_datetime_utc = datetime.utcnow().replace() end_datetime_utc = end_datetime_utc.replace(second=0, microsecond=0, tzinfo=None) time_difference = end_datetime_utc - start_datetime_utc time_difference_in_minutes = time_difference / timedelta(minutes=1) if time_difference_in_minutes < config.minutes_to_count: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "it's too early to calculate" + " for '" + virtual_meter['name'] + "'" # trim end_datetime_utc trimmed_end_datetime_utc = start_datetime_utc + timedelta(minutes=config.minutes_to_count) while trimmed_end_datetime_utc <= end_datetime_utc: trimmed_end_datetime_utc += timedelta(minutes=config.minutes_to_count) end_datetime_utc = trimmed_end_datetime_utc - timedelta(minutes=config.minutes_to_count) if end_datetime_utc <= start_datetime_utc: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "it's too early to calculate" + " for '" + virtual_meter['name'] + "'" print("start_datetime_utc: " + start_datetime_utc.isoformat()[0:19] + "end_datetime_utc: " + end_datetime_utc.isoformat()[0:19]) ############################################################################################################ # Step 2: parse the expression and get all meters, virtual meters, and # offline meters associated with the expression ############################################################################################################ cnx_system_db = None cursor_system_db = None try: cnx_system_db = mysql.connector.connect(**config.myems_system_db) cursor_system_db = cnx_system_db.cursor() except Exception as e: if cursor_system_db: cursor_system_db.close() if cnx_system_db: cnx_system_db.close() if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 2.1 of virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" meter_list_in_expression = list() virtual_meter_list_in_expression = list() offline_meter_list_in_expression = list() try: ######################################################################################################## # get all meters associated with the expression ######################################################################################################## cursor_system_db.execute(" SELECT m.id as meter_id, v.name as variable_name " " FROM tbl_meters m, tbl_variables v " " WHERE m.id = v.meter_id " " AND v.meter_type = 'meter' " " AND v.virtual_meter_id = %s ", (virtual_meter['id'], )) rows = cursor_system_db.fetchall() if rows is not None and len(rows) > 0: for row in rows: meter_list_in_expression.append({"meter_id": row[0], "variable_name": row[1].lower()}) ######################################################################################################## # get all virtual meters associated with the expression ######################################################################################################## cursor_system_db.execute(" SELECT m.id as virtual_meter_id, v.name as variable_name " " FROM tbl_virtual_meters m, tbl_variables v " " WHERE m.id = v.meter_id " " AND v.meter_type = 'virtual_meter' " " AND v.virtual_meter_id = %s ", (virtual_meter['id'],)) rows = cursor_system_db.fetchall() if rows is not None and len(rows) > 0: for row in rows: virtual_meter_list_in_expression.append({"virtual_meter_id": row[0], "variable_name": row[1].lower()}) ######################################################################################################## # get all offline meters associated with the expression ######################################################################################################## cursor_system_db.execute(" SELECT m.id as offline_meter_id, v.name as variable_name " " FROM tbl_offline_meters m, tbl_variables v " " WHERE m.id = v.meter_id " " AND v.meter_type = 'offline_meter' " " AND v.virtual_meter_id = %s ", (virtual_meter['id'],)) rows = cursor_system_db.fetchall() if rows is not None and len(rows) > 0: for row in rows: offline_meter_list_in_expression.append({"offline_meter_id": row[0], "variable_name": row[1].lower()}) except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 2.2 of virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" finally: if cursor_system_db: cursor_system_db.close() if cnx_system_db: cnx_system_db.close() ############################################################################################################ # Step 3: query energy consumption values from table meter hourly, virtual meter hourly # and offline meter hourly ############################################################################################################ print("getting energy consumption values from myems_energy_db.tbl_meter_hourly...") energy_meter_hourly = dict() if meter_list_in_expression is not None and len(meter_list_in_expression) > 0: try: for meter_in_expression in meter_list_in_expression: meter_id = str(meter_in_expression['meter_id']) query = (" SELECT start_datetime_utc, actual_value " " FROM tbl_meter_hourly " " WHERE meter_id = %s AND start_datetime_utc >= %s AND start_datetime_utc < %s " " ORDER BY start_datetime_utc ") cursor_energy_db.execute(query, (meter_id, start_datetime_utc, end_datetime_utc, )) rows_energy_values = cursor_energy_db.fetchall() if rows_energy_values is None or len(rows_energy_values) == 0: energy_meter_hourly[meter_id] = None else: energy_meter_hourly[meter_id] = dict() for row_energy_value in rows_energy_values: energy_meter_hourly[meter_id][row_energy_value[0]] = row_energy_value[1] except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 3.2 virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" print("getting energy consumption values from myems_energy_db.tbl_virtual_meter_hourly...") energy_virtual_meter_hourly = dict() if virtual_meter_list_in_expression is not None and len(virtual_meter_list_in_expression) > 0: try: for virtual_meter_in_expression in virtual_meter_list_in_expression: virtual_meter_id = str(virtual_meter_in_expression['virtual_meter_id']) query = (" SELECT start_datetime_utc, actual_value " " FROM tbl_virtual_meter_hourly " " WHERE virtual_meter_id = %s " " AND start_datetime_utc >= %s AND start_datetime_utc < %s " " ORDER BY start_datetime_utc ") cursor_energy_db.execute(query, (virtual_meter_id, start_datetime_utc, end_datetime_utc,)) rows_energy_values = cursor_energy_db.fetchall() if rows_energy_values is None or len(rows_energy_values) == 0: energy_virtual_meter_hourly[virtual_meter_id] = None else: energy_virtual_meter_hourly[virtual_meter_id] = dict() for row_energy_value in rows_energy_values: energy_virtual_meter_hourly[virtual_meter_id][row_energy_value[0]] = row_energy_value[1] except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 3.3 virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" print("getting energy consumption values from myems_energy_db.tbl_offline_meter_hourly...") energy_offline_meter_hourly = dict() if offline_meter_list_in_expression is not None and len(offline_meter_list_in_expression) > 0: try: for offline_meter_in_expression in offline_meter_list_in_expression: offline_meter_id = str(offline_meter_in_expression['offline_meter_id']) query = (" SELECT start_datetime_utc, actual_value " " FROM tbl_offline_meter_hourly " " WHERE offline_meter_id = %s " " AND start_datetime_utc >= %s AND start_datetime_utc < %s " " ORDER BY start_datetime_utc ") cursor_energy_db.execute(query, (offline_meter_id, start_datetime_utc, end_datetime_utc,)) rows_energy_values = cursor_energy_db.fetchall() if rows_energy_values is None or len(rows_energy_values) == 0: energy_offline_meter_hourly[offline_meter_id] = None else: energy_offline_meter_hourly[offline_meter_id] = dict() for row_energy_value in rows_energy_values: energy_offline_meter_hourly[offline_meter_id][row_energy_value[0]] = row_energy_value[1] except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 3.4 virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" ############################################################################################################ # Step 4: evaluate the equation with variables values from previous step # and save to table virtual meter hourly ############################################################################################################ print("getting common time slot of energy values for all meters...") common_start_datetime_utc = start_datetime_utc common_end_datetime_utc = end_datetime_utc if energy_meter_hourly is not None and len(energy_meter_hourly) > 0: for meter_id, energy_hourly in energy_meter_hourly.items(): if energy_hourly is None or len(energy_hourly) == 0: common_start_datetime_utc = None common_end_datetime_utc = None break else: if common_start_datetime_utc < min(energy_hourly.keys()): common_start_datetime_utc = min(energy_hourly.keys()) if common_end_datetime_utc > max(energy_hourly.keys()): common_end_datetime_utc = max(energy_hourly.keys()) print("getting common time slot of energy values for all virtual meters...") if common_start_datetime_utc is not None and common_end_datetime_utc is not None: if energy_virtual_meter_hourly is not None and len(energy_virtual_meter_hourly) > 0: for meter_id, energy_hourly in energy_virtual_meter_hourly.items(): if energy_hourly is None or len(energy_hourly) == 0: common_start_datetime_utc = None common_end_datetime_utc = None break else: if common_start_datetime_utc < min(energy_hourly.keys()): common_start_datetime_utc = min(energy_hourly.keys()) if common_end_datetime_utc > max(energy_hourly.keys()): common_end_datetime_utc = max(energy_hourly.keys()) print("getting common time slot of energy values for all offline meters...") if common_start_datetime_utc is not None and common_end_datetime_utc is not None: if energy_offline_meter_hourly is not None and len(energy_offline_meter_hourly) > 0: for meter_id, energy_hourly in energy_offline_meter_hourly.items(): if energy_hourly is None or len(energy_hourly) == 0: common_start_datetime_utc = None common_end_datetime_utc = None break else: if common_start_datetime_utc < min(energy_hourly.keys()): common_start_datetime_utc = min(energy_hourly.keys()) if common_end_datetime_utc > max(energy_hourly.keys()): common_end_datetime_utc = max(energy_hourly.keys()) print("evaluating the equation with SymPy...") normalized_values = list() ############################################################################################################ # Converting Strings to SymPy Expressions # The sympify function(that’s sympify, not to be confused with simplify) can be used to # convert strings into SymPy expressions. ############################################################################################################ try: expr = sympify(virtual_meter['equation'].lower()) print("the expression to be evaluated: " + str(expr)) current_datetime_utc = common_start_datetime_utc print("common_start_datetime_utc: " + str(common_start_datetime_utc)) print("common_end_datetime_utc: " + str(common_end_datetime_utc)) while common_start_datetime_utc is not None \ and common_end_datetime_utc is not None \ and current_datetime_utc <= common_end_datetime_utc: meta_data = dict() meta_data['start_datetime_utc'] = current_datetime_utc #################################################################################################### # create a dictionary of Symbol: point pairs #################################################################################################### subs = dict() #################################################################################################### # Evaluating the expression at current_datetime_utc #################################################################################################### if meter_list_in_expression is not None and len(meter_list_in_expression) > 0: for meter_in_expression in meter_list_in_expression: meter_id = str(meter_in_expression['meter_id']) actual_value = energy_meter_hourly[meter_id].get(current_datetime_utc, 0.0) subs[meter_in_expression['variable_name']] = actual_value if virtual_meter_list_in_expression is not None and len(virtual_meter_list_in_expression) > 0: for virtual_meter_in_expression in virtual_meter_list_in_expression: virtual_meter_id = str(virtual_meter_in_expression['virtual_meter_id']) actual_value = energy_virtual_meter_hourly[virtual_meter_id].get(current_datetime_utc, 0.0) subs[virtual_meter_in_expression['variable_name']] = actual_value if offline_meter_list_in_expression is not None and len(offline_meter_list_in_expression) > 0: for offline_meter_in_expression in offline_meter_list_in_expression: offline_meter_id = str(offline_meter_in_expression['offline_meter_id']) actual_value = energy_offline_meter_hourly[offline_meter_id].get(current_datetime_utc, 0.0) subs[offline_meter_in_expression['variable_name']] = actual_value #################################################################################################### # To numerically evaluate an expression with a Symbol at a point, # we might use subs followed by evalf, # but it is more efficient and numerically stable to pass the substitution to evalf # using the subs flag, which takes a dictionary of Symbol: point pairs. #################################################################################################### meta_data['actual_value'] = expr.evalf(subs=subs) normalized_values.append(meta_data) current_datetime_utc += timedelta(minutes=config.minutes_to_count) except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 4.1 virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" print("saving energy values to table virtual meter hourly...") if len(normalized_values) > 0: try: add_values = (" INSERT INTO tbl_virtual_meter_hourly " " (virtual_meter_id, start_datetime_utc, actual_value) " " VALUES ") for meta_data in normalized_values: add_values += " (" + str(virtual_meter['id']) + "," add_values += "'" + meta_data['start_datetime_utc'].isoformat()[0:19] + "'," add_values += str(meta_data['actual_value']) + "), " print("add_values:" + add_values) # trim ", " at the end of string and then execute cursor_energy_db.execute(add_values[:-2]) cnx_energy_db.commit() except Exception as e: if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return "Error in step 4.2 virtual meter worker " + str(e) + " for '" + virtual_meter['name'] + "'" if cursor_energy_db: cursor_energy_db.close() if cnx_energy_db: cnx_energy_db.close() return None