Jac Cloud Scheduler

Supported specs

NAME	TYPE	DESCRIPTION	DEFAULT
trigger	str	trigger type (cron, interval, date)	N/A
node	str or None	entry node if necessary, defaults to root	None
args	list[Any] or None	list of arguments to initialize the walker	None
kwargs	dict[str, Any] or None	dict of keyword arguments to initialize the walker	None
max_instances	int	max simultaneous running job per walker type	1
next_run_time	datetime or None	target date before the first trigger will happen	None
propagate	bool	if multiple jac-cloud service can trigger at the same time or first service only per trigger only	false
save	bool	if walker instance will be save to the db including the results	false

cron type trigger

• You need to add additional specs for cron

NAME	TYPES	DESCRIPTION	DEFAULT
year	int or str	4-digit year	*
month	int or str	month (1-12)	*
day	int or str	day of month (1-31)	*
week	int or str	ISO week (1-53)	*
day_of_week	int or str	number or name of weekday (0-6 or mon,tue,wed,thu,fri,sat,sun)	*
hour	int or str	hour (0-23)	*
minute	int or str	minute (0-59)	*
second	int or str	second (0-59)	*
start_date	datetime or str or None	earliest possible date/time to trigger on (inclusive)	None
end_date	datetime or str or None	latest possible date/time to trigger on (inclusive)	None

Example

walker walker_cron {
    has arg1: int;
    has arg2: str;
    has kwarg1: int = 3;
    has kwarg2: str = "4";

    can enter with `root entry {
        print("I am a scheduled walker!")
    }

    class __specs__ {
        has private: bool = True;
        has schedule: dict = {
            "trigger": "cron",
            "args": [1, "2"],
            "kwargs": {
                "kwarg1": 30,
                "kwarg2": "40"
            },
            "save": True
        };
    }
}

interval type trigger

• You need to add additional specs for interval

NAME	TYPES	DESCRIPTION	DEFAULT
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	1
start_date	datetime or str or None	starting point for the interval calculation
end_date	datetime or str or None	latest possible date/time to trigger on

walker walker_interval {
    has arg1: int;
    has arg2: str;
    has kwarg1: int = 3;
    has kwarg2: str = "4";

    can enter with `root entry {
        print("I am a scheduled walker!")
    }

    class __specs__ {
        has private: bool = True;
        has schedule: dict = {
            "trigger": "interval",
            "args": [1, "2"],
            "kwargs": {
                "kwarg1": 30,
                "kwarg2": "40"
            },
            "seconds": 5,
            "save": True
        };
    }
}

date type trigger

• You need to add additional specs for interval

NAME	TYPES	DESCRIPTION	DEFAULT
run_date	datetime or str	the date/time to run the job at

walker walker_date {
    has arg1: int;
    has arg2: str;
    has kwarg1: int = 3;
    has kwarg2: str = "4";

    can enter with `root entry {
        print("I am a scheduled walker!")
    }

    class __specs__ {
        has private: bool = True;
        has schedule: dict = {
            "trigger": "date",
            "args": [1, "2"],
            "kwargs": {
                "kwarg1": 30,
                "kwarg2": "40"
            },
            "run_date": "2025-04-30T11:12:00+00:00",
            "save": True
        };
    }
}

Jac Cloud Optional Task

• This will only be enabled if you have set TASK_CONSUMER_CRON_SECOND

Example Use Case

import from jac_cloud.plugin.implementation {create_task}

node TaskCounter {
    has val: int = 0;
}

walker get_or_create_counter {
    can enter1 with `root entry {
        tc = TaskCounter();
        here ++> tc;

        report tc;
    }

    can enter2 with TaskCounter entry {
        report here;
    }
}

walker increment_counter {
    has val: int;

    can enter with TaskCounter entry {
        here.val += self.val;
    }

    class __specs__ {
        has private: bool = True;
    }
}

walker trigger_counter_task {
    can enter with `root entry {
        tcs = [-->(`?TaskCounter)];
        if tcs {
            report create_task(increment_counter(val=1), tcs[0]);
        }
    }
}

• trigger_counter_task walker will only create walker task and will be consumed by Task Consumer
• this will report walker id that can be used to retrieve it again
• task will be saved to db and also in redis
• the polling mechanism will use redis to avoid traffic to db
  • lowest polling trigger will be 1 second. Can be set to TASK_CONSUMER_CRON_SECOND
• the consume flow will be atomic and only one jac-cloud instance can process a task
• if redis is cleaned up, upon running of jac-cloud service, it will repopulate pending task to redis again
• if ever multiple services tries to repopulate pending task to redis, since we are using atomic operations, if the task is already started it will be skipped by other services