Workflow Engine
Overview
SCANUE v22’s workflow engine is built on LangGraph, providing sophisticated orchestration capabilities for multi-agent systems. The engine manages complex workflows with conditional routing, state persistence, and human-in-the-loop integration.
Core Architecture
State Management
The workflow maintains persistent state across all execution phases:
- Global State: Shared information accessible by all agents
- Agent State: Private state maintained by individual agents
- Transition State: Temporary data during workflow transitions
Conditional Routing
Dynamic workflow routing based on:
- Agent Responses: Decisions based on agent output
- External Conditions: Environmental or user-driven factors
- Performance Metrics: Routing based on system performance
Error Handling
Comprehensive error management including:
- Graceful Degradation: Continuing operation despite partial failures
- Rollback Mechanisms: Reverting to previous stable states
- Recovery Strategies: Automatic and manual recovery options
Workflow Components
Stages
The workflow is organized into distinct stages:
- Initialization: System setup and agent preparation
- Processing: Core task execution by agents
- Coordination: Inter-agent communication and synchronization
- Decision Points: Human-in-the-loop interaction opportunities
- Finalization: Result compilation and cleanup
Transitions
Smooth transitions between stages with:
- Validation: Ensuring prerequisites are met
- State Transfer: Moving relevant data between stages
- Cleanup: Releasing unnecessary resources
Example Workflow Structure
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from workflow import SCANUEWorkflow
from agents.dlpfc import DLPFCAgent
from agents.specialized import SpecializedAgent
# Initialize workflow
workflow = SCANUEWorkflow()
# Define stages
workflow.add_stage("analysis", AnalysisStage())
workflow.add_stage("decision", DecisionStage())
workflow.add_stage("execution", ExecutionStage())
# Configure transitions
workflow.add_transition("analysis", "decision", condition="analysis_complete")
workflow.add_transition("decision", "execution", condition="decision_approved")
Human-in-the-Loop Integration
Interactive Decision Points
Strategic placement of human feedback opportunities:
- Critical Decisions: High-impact choices requiring human judgment
- Quality Gates: Human validation of intermediate results
- Exception Handling: Human intervention for unexpected scenarios
Feedback Mechanisms
- Real-time Input: Live interaction during workflow execution
- Batch Feedback: Reviewing and approving multiple decisions
- Asynchronous Review: Time-delayed feedback for non-urgent decisions
Implementation Example
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from debug.demonstrate_hitl import setup_hitl_workflow
# Setup HITL workflow
workflow = setup_hitl_workflow()
# Add human decision point
workflow.add_human_checkpoint(
stage="critical_decision",
prompt="Please review the analysis results:",
options=["approve", "modify", "reject"],
timeout=300 # 5 minutes
)
Advanced Features
Parallel Execution
Execute multiple agents simultaneously:
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# Parallel agent execution
workflow.execute_parallel([
("agent_1", task_1),
("agent_2", task_2),
("agent_3", task_3)
])
Dynamic Agent Selection
Choose agents based on runtime conditions:
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# Dynamic agent selection
agent = workflow.select_agent(
task_type="analysis",
workload_level="high",
expertise_required="statistical"
)
Workflow Composition
Combine multiple workflows:
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# Compose workflows
main_workflow = SCANUEWorkflow()
sub_workflow = AnalysisWorkflow()
main_workflow.embed_workflow(sub_workflow, stage="analysis")
Monitoring and Debugging
Real-time Monitoring
Track workflow execution in real-time:
- Stage Progress: Current stage and completion percentage
- Agent Status: Individual agent states and activities
- Performance Metrics: Execution time, resource usage, success rates
Debug Utilities
Comprehensive debugging tools:
- Workflow Visualization: Graphical representation of workflow structure
- State Inspection: Detailed view of workflow and agent states
- Execution Traces: Step-by-step execution history
Debug Scripts
The system includes several debug utilities:
debug_workflow.py
: General workflow debuggingdebug_stage_transitions.py
: Stage transition analysisdebug_langgraph_mapping.py
: LangGraph integration debuggingdemonstrate_hitl.py
: Human-in-the-loop demonstration
Performance Optimization
Execution Strategies
- Eager Execution: Immediate processing for time-critical tasks
- Lazy Evaluation: Deferred processing for resource optimization
- Batch Processing: Grouping similar tasks for efficiency
Resource Management
- Memory Pooling: Efficient memory allocation and reuse
- Connection Pooling: Optimized external service connections
- Load Balancing: Distributing work across available resources
Caching Strategies
- Result Caching: Storing computation results for reuse
- State Caching: Persisting workflow states for quick recovery
- Agent Model Caching: Caching trained models for faster initialization
Configuration
Workflow Configuration
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workflow_config = {
"max_execution_time": 3600, # 1 hour
"retry_attempts": 3,
"parallel_execution": True,
"human_timeout": 300, # 5 minutes
"state_persistence": True
}
workflow = SCANUEWorkflow(config=workflow_config)
Agent Configuration
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agent_config = {
"dlpfc_agent": {
"memory_size": 1000,
"attention_span": 10,
"decision_threshold": 0.8
},
"specialized_agents": {
"max_concurrent": 5,
"timeout": 60
}
}
Testing Workflows
Unit Testing
Test individual workflow components:
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def test_stage_transition():
workflow = SCANUEWorkflow()
result = workflow.transition_to_stage("analysis")
assert result.success == True
Integration Testing
Test complete workflow execution:
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def test_full_workflow():
workflow = setup_test_workflow()
result = workflow.execute(test_input)
assert result.completion_status == "success"
Performance Testing
Measure workflow performance:
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def test_workflow_performance():
workflow = SCANUEWorkflow()
start_time = time.time()
result = workflow.execute(large_dataset)
execution_time = time.time() - start_time
assert execution_time < 300 # 5 minutes
For more detailed information about workflow implementation, see our technical documentation.