基于json文件实现的gearman任务自动重启

一：在gearman任务失败后，调用task_failed

def task_failed(task, *args):
    info = '
'.join(args)
    datetime = local_datetime()
    text = '{} FAILED:
{}
当前响应worker已关闭
{}
-->【{}】'.format(task, info, datetime, task)
    print(text)
    check_frequency(task)

二：打印失败信息后，调用check_frequency检查任务5分钟内的重启次数

def check_frequency(task):
    instance = TaskReloadMonitor()
    now = time.time()
    task_info = instance.open(task.lower())
    if not task_info:
        return
    worker = task_info.get('worker')
    last_time = task_info.get('last_time')
    if not last_time:
        task_info['timer'] = 1
        task_info['last_time'] = now
        instance.write()
        task_reload(task, worker, task_info['timer'])
        return
    if int(now) - int(last_time) > 300:
        task_info['timer'] = 1
        task_info['last_time'] = now
        instance.write()
        task_reload(task, worker, task_info['timer'])
        return
    timer = task_info.get('timer')
    if not (timer + 1 > 3):
        task_info['timer'] = timer + 1
        task_info['last_time'] = now
        instance.write()
        task_reload(task, worker, task_info['timer'])

三：确认重启任务后，利用subprocess重启任务，subprocess.Popen方法可以非阻塞运行cmd命令

def task_reload(task, worker, timer):
    from coursepoints.settings import BASE_DIR
    manage = os.path.join(BASE_DIR, 'manage.py')
    datetime = local_datetime()
    command = 'python {} {}'.format(manage, worker)
    subprocess.Popen(command, shell=True)
    text = '-->task reload:{}
-->timer:{}
-->{}'.format(task, timer, datetime)
    print(text)

class TaskReloadMonitor():
    def __init__(self):
        pass

    @property
    def path(self):
        path = Path(__file__).parent.joinpath('task.json')
        return path

    def open(self, task):
        try:
            f = open(self.path, 'r', encoding='utf8')
            data = json.loads(f.read())
            f.close()
            self.task_data = data
            task_info = data.get(task)
            return task_info
        except Exception as e:
            print(e)
            return None

    def write(self):
        try:
            f = open(self.path, 'w', encoding='utf8')
            data = json.dumps(self.task_data)
            f.write(data)
            f.close()
        except Exception as e:
            print(e)

{
  "pptconvert": {
    "worker": "pptconvert",
    "timer": 1,
    "last_time": 1555356612.9220166
  },
  "screencapture": {
    "worker": "screencapture",
    "timer": 0
  },
  "snapscreen": {
    "worker": "snapscreen",
    "timer": 1,
    "last_time": 1555441223.166838
  }
}