Scheduled Tasks

Scheduled Tasks (tasks.NormalType) are the most fundamental task type in the JitTask framework, similar to Cron jobs in Linux. They rely entirely on the system clock and preset configurations to trigger, making them suitable for periodic background jobs that are not strongly correlated with specific business data rows, such as:

• Daily data cleanup at midnight
• Periodic statistical reporting
• System status inspection

The Scheduled Task element follows a hierarchical structure: Meta (tasks.Meta) → Type (tasks.NormalType) → Instance. Developers can quickly create scheduled task instance elements using visual development tools.

Quick Start

Creating an Instance Element

Directory Structure

Create a new task directory (e.g., MyDailyJob) under the tasks/ directory. The standard structure is as follows:

tasks/
└── MyDailyJob/           # [Directory] Task element name
    ├── e.json            # [File] Core configuration file
    ├── inner.py          # [File] (Optional) Internal execution logic code
    └── __init__.py       # [File] Python package identifier

e.json

tasks/MyDailyJob/e.json

{
  "type": "tasks.NormalType",
  "funcType": "Global",
  "func": "services.DataSyncService.syncUserData",
  "title": "Daily Data Sync",
  "timerCfg": {
    "startTime": "2024-01-01 09:00:00",
    "endTime": "2024-12-31 18:00:00",
    "repeat": {
      "repeatType": "day",
      "period": 1
    },
    "skipHoliday": 1
  },
  "enable": 1,
  "backendBundleEntry": "."
}

inner.py

tasks/MyDailyJob/inner.py

from jit.commons.utils.logger import log

def customFunc():
    """
    Function name must be customFunc
    """
    # Business logic...
    # When `funcType` is `Global`, this function does not need to be implemented.
    pass

init.py

tasks/MyDailyJob/__init__.py

# -*-coding:utf-8-*-

from .inner import customFunc

When funcType is Global, the execution function is a service function, not customFunc.

Element Configuration

e.json Configuration

Field Name	Type	Required	Description	Example
type	String	Yes	Fixed value	"tasks.NormalType"
title	String	Yes	Task display name	"Daily Data Sync"
enable	Integer	No	1: Enable, 0: Disable (Default: 0)	1
funcType	String	Yes	Function type: "Inner" or "Global"	"Inner"
func	String	Conditional	Required when funcType is "Global", points to the service function path	"services.MySvc.run"
backendBundleEntry	String	Yes	Backend load entry, fixed as "."	"."

timerCfg Configuration

This is the core part of the configuration, determining when the task executes.

Parameter Name	Type	Required	Description	Example Value
startTime	String	Yes	First execution time, format: yyyy-MM-dd HH:mm:ss	"2024-01-01 09:00:00"
endTime	String	No	Task termination time; the task stops automatically after this time	"2024-12-31 18:00:00"
skipHoliday	Integer	No	Whether to skip holidays: 1 to skip, 0 not to skip	1
repeat	Object	Yes	Configuration object for repetition	See repeat configuration

Explanation:

• If the current time is later than startTime and the task has not been executed yet, the system will calculate the next scheduled execution time based on the repeat rules.
• If the scheduled execution time falls on a holiday (based on the system calendar) and skipHoliday is 1, it will be postponed by one cycle.

repeat Configuration

The repeatType in the repeat object determines the specific repetition strategy.

Parameter Name	Type	Required	Description	Optional Values
repeatType	String	Yes	Repeat type	"year", "month", "week", "day", "hour", "minute", "normal"
period	Integer	Yes	Repeat period, indicating the interval count	Positive Integer

Basic Repeat Types:

• Daily: "repeatType": "day", "period": 1 (Every day)
• Hourly: "repeatType": "hour", "period": 2 (Every 2 hours)
• Every 30 Minutes: "repeatType": "minute", "period": 30
• No Repeat: "repeatType": "normal" (Executes only once at startTime)

Execution Function

Service Function (Recommended)

Suitable for reusing existing Service logic.

Ensure a service with fullName as services.DataSyncService exists and contains the syncUserData function.

services/DataSyncService/service.py

from datatypes.Meta import datatypes
from services.NormalType import NormalService

class DataSyncService(NormalService):

  def syncUserData(self):
      """Service function example"""
      # Business logic...
      return {"status": "completed"}

Internal Task Function

Suitable for scenarios where the logic belongs exclusively to the task and does not need to be reused. The function is implemented in inner.py under the element directory, with the function name fixed as customFunc.

tasks/MyDailyJob/inner.py

from jit.commons.utils.logger import log

def customFunc():
    """
    Function name must be customFunc
    No arguments
    """
    log.info("Starting daily task execution...")
    
    # Get user model for data operations
    UserModel = app.getElement("models.UserModel")
    users = UserModel.query(filter="Q(status='active')")
    
    for user in users["rowDatas"]:
        # Execute business logic
        log.info(f"Processing user: {user.name.value}")
    
    log.info("Task execution completed")
    return {"status": "success", "processedCount": len(users["rowDatas"])}

Debugging and Notes

1. Effective Time: Changes to e.json usually require a restart of the backend service to take effect.

2. Exception Handling:

   • If the code throws an exception, the task status will become error.
   • Important: If an exception causes the program to crash and is not caught, it may affect the generation of the next task (because the next task is generated during the afterReturn phase of the current task). It is recommended to use try...except protection within customFunc.

3. Timeout: The default timeout is 12 hours. If a task execution exceeds this time, it may be marked as expired by the system.