Task Scheduler

22. Task Scheduler Center System Design¶

22.1 System Overview¶

The Task Scheduler Center serves as the automated operations hub for the quantitative trading system, providing centralized management of all scheduled tasks and automated operations. This system enables unattended operation of the entire trading platform through intelligent task scheduling and execution.

22.1.1 Core Objectives¶

Centralized Task Management: - Unified Scheduling: Single point of control for all system tasks - Automated Operations: Eliminate manual intervention in routine operations - Reliability Assurance: Robust task execution with failure recovery - Scalable Architecture: Support for distributed task execution

Operational Excellence: - 24/7 Automation: Continuous system operation without human oversight - Intelligent Scheduling: Time-based and event-driven task execution - Comprehensive Monitoring: Real-time task status and performance tracking - Future-Ready: Foundation for advanced workflow orchestration

22.2 Architecture Design¶

22.2.1 Microservice Architecture¶

Task Scheduler Center Service:

services/task-scheduler-center/
├── src/
│   ├── main.py                 # Service entry point
│   ├── scheduler/              # Scheduling engine
│   │   ├── task_definitions.py # Predefined task definitions
│   │   ├── scheduler_engine.py # Core scheduling logic
│   ├── executor/               # Task execution framework
│   │   ├── task_executor.py    # Task execution and retry logic
│   ├── monitor/                # Task monitoring and logging
│   │   ├── task_monitor.py     # Task status tracking
│   ├── api/                    # REST API interface
│   │   ├── scheduler_api.py    # Task management endpoints
│   ├── config.py               # Configuration management
│   ├── requirements.txt        # Dependencies
├── Dockerfile                  # Container configuration

22.2.2 Core Components¶

Task Definition Module: - Predefined Tasks: Standard system operations (backtesting, optimization, reporting) - Custom Tasks: User-defined task definitions - Task Metadata: Execution parameters, dependencies, and constraints - Task Templates: Reusable task patterns for common operations

Scheduling Engine: - Cron Expression Support: Flexible time-based scheduling - Event-Driven Triggers: Task execution based on system events - Dependency Management: Task execution order and prerequisites - Resource Allocation: Intelligent resource distribution across tasks

Task Executor: - Execution Framework: Unified task execution environment - Retry Mechanism: Automatic failure recovery with exponential backoff - Timeout Management: Task execution time limits and cancellation - Resource Isolation: Task execution in isolated environments

Task Monitor: - Status Tracking: Real-time task execution status - Performance Metrics: Task execution time and resource usage - Failure Analysis: Detailed error logging and analysis - Historical Records: Complete task execution history

22.3 Task Categories and Definitions¶

22.3.1 System Maintenance Tasks¶

Daily Backtesting: - Schedule: Daily at 2:00 AM - Purpose: Comprehensive strategy performance validation - Execution: Call backtest-engine for full system backtesting - Output: Performance reports and strategy validation results

Weekly Parameter Optimization: - Schedule: Weekly on Saturday at 3:00 AM - Purpose: Strategy parameter recalibration - Execution: Trigger strategy-optimizer for parameter updates - Output: Optimized parameters and performance metrics

Daily Performance Reporting: - Schedule: Daily at 6:00 AM - Purpose: Generate comprehensive performance reports - Execution: Call performance-service for report generation - Output: Strategy and account performance reports

22.3.2 Data Management Tasks¶

Exchange Rate Updates: - Schedule: Every 4 hours - Purpose: Maintain current exchange rates - Execution: Update exchange rate service - Output: Updated currency conversion rates

Data Snapshot Rebuild: - Schedule: Daily at 1:00 AM - Purpose: Rebuild market data snapshots - Execution: Trigger data-snapshot-service - Output: Fresh market data snapshots

Strategy Runner Restart: - Schedule: Weekly on Sunday at 4:00 AM - Purpose: Refresh strategy execution environments - Execution: Restart strategy-runner services - Output: Clean strategy execution state

22.3.3 Custom Task Support¶

One-Time Tasks: - Manual Execution: Immediate task execution - Scheduled Execution: Future one-time task scheduling - Event-Triggered: Task execution based on specific events

Periodic Tasks: - Fixed Intervals: Regular task execution at specified intervals - Business Hours: Task execution during trading hours only - Market Conditions: Task execution based on market state

Cron Expression Tasks: - Flexible Scheduling: Complex scheduling patterns - Multiple Triggers: Multiple time-based triggers per task - Conditional Execution: Task execution based on conditions

22.4 Technology Stack¶

22.4.1 Core Technologies¶

Scheduling Framework: - APScheduler: Advanced Python scheduling library - Cron Support: Full cron expression compatibility - Async Execution: Asynchronous task execution support - Persistent Storage: Task schedule persistence

Execution Environment: - Docker Containers: Isolated task execution environments - Resource Limits: CPU and memory allocation per task - Network Isolation: Secure task execution network - Volume Mounting: Data access for task execution

Monitoring and Logging: - Prometheus: Task execution metrics collection - Grafana: Task monitoring dashboards - Structured Logging: Comprehensive task execution logs - Alert Management: Task failure and performance alerts

22.4.2 Integration Technologies¶

Message Communication: - NATS: Task execution event publishing - REST APIs: Task management and status queries - WebSocket: Real-time task status updates - Event Streaming: Task execution event streaming

Data Storage: - PostgreSQL: Task definitions and execution history - Redis: Task status caching and session management - Time-Series DB: Task performance metrics storage - File Storage: Task output and log file storage

22.5 API Design¶

22.5.1 Task Management Endpoints¶

Task Definition:

POST   /api/v1/tasks/define           # Define new task
GET    /api/v1/tasks/list             # List all tasks
PUT    /api/v1/tasks/{task_id}        # Update task definition
DELETE /api/v1/tasks/{task_id}        # Delete task

Task Scheduling:

POST   /api/v1/tasks/{task_id}/schedule    # Schedule task execution
POST   /api/v1/tasks/{task_id}/unschedule  # Remove task from schedule
POST   /api/v1/tasks/{task_id}/execute     # Execute task immediately
GET    /api/v1/tasks/{task_id}/schedule    # Get task schedule

Task Monitoring:

GET    /api/v1/tasks/{task_id}/status     # Get current task status
GET    /api/v1/tasks/{task_id}/logs       # Get task execution logs
GET    /api/v1/tasks/{task_id}/history    # Get task execution history
GET    /api/v1/tasks/metrics              # Get task performance metrics

22.5.2 Real-time Updates¶

WebSocket Endpoints:

/ws/tasks/status                         # Real-time task status updates
/ws/tasks/execution                      # Real-time execution events
/ws/tasks/alerts                         # Task failure and performance alerts
/ws/tasks/metrics                        # Real-time performance metrics

22.6 Frontend Integration¶

22.6.1 Task Management Dashboard¶

Task Overview Panel: - Task List: Comprehensive view of all scheduled tasks - Status Indicators: Visual task status and health indicators - Schedule Display: Next execution time and frequency - Quick Actions: Manual execution and schedule modification

Task Execution Panel: - Real-time Monitoring: Live task execution status - Execution History: Historical task execution records - Performance Metrics: Task execution time and success rates - Failure Analysis: Detailed error logs and troubleshooting

Task Configuration Panel: - Task Definition: Create and modify task definitions - Schedule Management: Configure execution schedules - Dependency Setup: Define task dependencies and order - Resource Allocation: Configure execution resources

22.6.2 Interactive Features¶

Visualization Tools: - Task Timeline: Visual representation of task schedules - Execution Flow: Task dependency and execution flow diagrams - Performance Charts: Task execution performance trends - Resource Usage: Task resource consumption visualization

Management Tools: - Bulk Operations: Multi-task scheduling and management - Template Management: Reusable task template library - Schedule Optimization: Intelligent schedule optimization suggestions - Conflict Detection: Schedule conflict identification and resolution

22.7 Operational Benefits¶

22.7.1 Automation Excellence¶

Benefit	Impact
24/7 Operation	Continuous system operation without manual intervention
Consistent Execution	Reliable and repeatable task execution
Error Reduction	Elimination of manual operation errors
Operational Efficiency	Reduced operational overhead and costs

22.7.2 System Reliability¶

Advantage	Business Value
Proactive Maintenance	Automated system maintenance and optimization
Failure Recovery	Automatic task retry and recovery mechanisms
Performance Monitoring	Continuous system performance tracking
Predictive Maintenance	Early detection of potential issues

22.8 Implementation Roadmap¶

22.8.1 Phase 1: Foundation (Weeks 1-2)¶

Basic Scheduler: Core scheduling engine implementation
Task Definitions: Predefined system maintenance tasks
Simple API: Basic task management endpoints
Basic Frontend: Task list and status display

22.8.2 Phase 2: Advanced Features (Weeks 3-4)¶

Retry Mechanism: Automatic failure recovery
Resource Management: Task resource allocation and isolation
Monitoring Integration: Comprehensive task monitoring
Advanced Scheduling: Complex scheduling patterns

22.8.3 Phase 3: Automation (Weeks 5-6)¶

System Integration: Integration with all system components
Custom Tasks: User-defined task support
Event-Driven Triggers: Event-based task execution
Performance Optimization: Task execution optimization

22.8.4 Phase 4: Production Ready (Weeks 7-8)¶

Distributed Execution: Multi-node task execution
Advanced Analytics: Task performance analytics
Workflow Orchestration: Complex workflow support
Enterprise Features: Institutional-grade task management

22.9 Integration with Existing System¶

22.9.1 Service Integration¶

Backtest Engine Integration:

Task Scheduler → Daily Backtest Task → Backtest Engine → Performance Reports

Strategy Optimizer Integration:

Task Scheduler → Weekly Optimization Task → Strategy Optimizer → Updated Parameters

Performance Service Integration:

Task Scheduler → Daily Report Task → Performance Service → Generated Reports

22.9.2 Data Flow Integration¶

Task Execution Events: - Task Start: Task execution initiation events - Task Completion: Successful task completion events - Task Failure: Task failure and error events - Task Metrics: Task performance and resource usage metrics

System Health Monitoring: - Task Health: Individual task health and performance - System Health: Overall system health based on task execution - Resource Health: System resource usage and availability - Dependency Health: Task dependency and prerequisite health

22.10 Business Value¶

22.10.1 Operational Excellence¶

Benefit	Impact
Unattended Operation	24/7 system operation without manual intervention
Consistent Performance	Reliable and predictable system performance
Reduced Operational Risk	Elimination of manual operation errors
Scalable Operations	Support for unlimited task automation

22.10.2 Cost Efficiency¶

Advantage	Business Value
Reduced Manual Work	Significant reduction in operational overhead
Improved Reliability	Higher system uptime and performance
Faster Response	Automated response to system events
Predictable Operations	Consistent and reliable system behavior