APScheduler (focus)

Timing correction

• Demand: mysql and redis two systems, increase data successfully mysql, redis not been added, so that the data of the two systems might deviation, so the need for regular data and redis synchronize mysql
• Solution: to perform regular tasks once a day, let mysql data and synchronize data redis

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• crontab
  • Linux system is a built-in command, depending on the linux system, no dynamic management tasks (cancel / suspend / modify the task configuration)
  • Usage scenarios: suitable for ordinary static task
• apscheduler
  • Independent timer program, you can easily manage scheduled tasks
  • Usage scenarios: dynamically generating / management tasks, after 30 minutes following a single period can be
  • installation pip install apscheduler
  • It supports three trigger
    • date performed only once
      
    • interval execution cycle parameters 时间间隔
    • cron execution cycle parameters 时间

Scheduler Scheduler

Responsible for managing the regular tasks

BlockingScheduler: Use as a separate process

  from apscheduler.schedulers.blocking import BlockingScheduler

  scheduler = BlockingScheduler()
  scheduler.start()  # 此处程序会发生阻塞

BackgroundScheduler: Use the frame (such as Django, Flask) of

  from apscheduler.schedulers.background import BackgroundScheduler

  scheduler = BackgroundScheduler()
  scheduler.start()  # 此处程序不会发生阻塞

Actuator executors

When the scheduled task execution, process or thread way to perform a task

ThreadPoolExecutor

  from apscheduler.executors.pool import ThreadPoolExecutor
  ThreadPoolExecutor(max_workers)  
  ThreadPoolExecutor(20) # 最多20个线程同时执行

Instructions

  executors = {
      'default': ThreadPoolExecutor(20)
  }
  scheduler = BackgroundScheduler(executors=executors)

ProcessPoolExecutor

  from apscheduler.executors.pool import ProcessPoolExecutor
  ProcessPoolExecutor(max_workers)
  ProcessPoolExecutor(5) # 最多5个进程同时执行

Instructions

  executors = {
      'default': ProcessPoolExecutor(3)
  }
  scheduler = BackgroundScheduler(executors=executors)

Trigger Trigger

Timing specifying the timing of task execution

1) date run at a specific date and time

from datetime import date

# 在2019年11月6日00:00:00执行
sched.add_job(my_job, 'date', run_date=date(2009, 11, 6))

# 在2019年11月6日16:30:05
sched.add_job(my_job, 'date', run_date=datetime(2009, 11, 6, 16, 30, 5))
sched.add_job(my_job, 'date', run_date='2009-11-06 16:30:05')

# 立即执行
sched.add_job(my_job, 'date')  
sched.start()

2） interval 经过指定的时间间隔执行
weeks (int) – number of weeks to wait
days (int) – number of days to wait
hours (int) – number of hours to wait
minutes (int) – number of minutes to wait
seconds (int) – number of seconds to wait
start_date (datetime|str) – starting point for the interval calculation
end_date (datetime|str) – latest possible date/time to trigger on
timezone (datetime.tzinfo|str) – time zone to use for the date/time calculations

from datetime import datetime

# 每两小时执行一次
sched.add_job(job_function, 'interval', hours=2)

# 在2010年10月10日09:30:00 到2014年6月15日的时间内，每两小时执行一次
sched.add_job(job_function, 'interval', hours=2, start_date='2010-10-10 09:30:00', end_date='2014-06-15 11:00:00')

3） cron 按指定的周期执行
year (int|str) – 4-digit year
month (int|str) – month (1-12)
day (int|str) – day of the (1-31)
week (int|str) – ISO week (1-53)
day_of_week (int|str) – number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun)
hour (int|str) – hour (0-23)
minute (int|str) – minute (0-59)
second (int|str) – second (0-59)
start_date (datetime|str) – earliest possible date/time to trigger on (inclusive)
end_date (datetime|str) – latest possible date/time to trigger on (inclusive)
timezone (datetime.tzinfo|str) – time zone to use for the date/time calculations(defaults to scheduler timezone)

# 在6、7、8、11、12月的第三个周五的00:00, 01:00, 02:00和03:00 执行
sched.add_job(job_function, 'cron', month='6-8,11-12', day='3rd fri', hour='0-3')

# 在2014年5月30日前的周一到周五的5:30执行
sched.add_job(job_function, 'cron', day_of_week='mon-fri', hour=5, minute=30, end_date='2014-05-30')

Code