Workflow Connection Issues

When nodes don’t connect properly or data doesn’t flow between them, your entire workflow breaks down. This guide helps you diagnose and fix connection and data flow problems.

🔗 Quick Connection Diagnostics

Check these first:

🔗 Visual connections exist - Ensure lines connect node outputs to inputs
🔗 Data types match - Verify output type matches input requirements
🔗 Execution order is correct - Check that dependencies run before dependent nodes
🔗 No circular dependencies - Ensure nodes don’t create infinite loops
🔗 All required inputs connected - Verify mandatory inputs have data sources

🚫 Common Connection Problems

Nodes Not Connecting

Visual Connection Issues

Symptoms:

Cannot draw connection lines between nodes
Connection lines disappear after creation
Nodes appear connected but don’t pass data

Connection troubleshooting table:

Problem	Cause	Solution
Cannot create connection	Incompatible data types	Check input/output type compatibility
Connection disappears	Invalid connection attempt	Verify connection endpoints are correct
Multiple connections to input	Input already connected	Remove existing connection first
Connection to wrong port	Clicked wrong connector	Ensure connection to correct input/output

Visual connection verification:

graph LR
    A[Source Node] -->|Data Type: String| B[Target Node]
    C[Source Node] -->|Data Type: Number| D[Target Node]
    E[Source Node] -->|❌ Type Mismatch| F[Target Node]

    style E fill:#ffebee
    style F fill:#ffebee

Data Type Mismatches

Common type compatibility issues:

Output Type	Compatible Inputs	Incompatible Inputs	Solution
String	Text, Any	Number (strict)	Use conversion node
Number	Numeric, Any	String (strict)	Use formatting node
Array	List, Collection	Single item	Use array processing
Object	Structured data	Primitive types	Use field extraction
Boolean	True/False, Any	Complex objects	Use conditional logic

Type conversion examples:

// String to Number conversion
const numberValue = parseFloat(stringValue);

// Number to String conversion
const stringValue = numberValue.toString();

// Array to String conversion
const stringValue = arrayValue.join(', ');

// Object to String conversion
const stringValue = JSON.stringify(objectValue);

Data Not Flowing

Execution Order Problems

Symptoms:

Nodes execute in wrong order
Dependent nodes run before their dependencies
Data arrives after node has already executed

Execution flow debugging:

graph TB
    A[Trigger Node] --> B[Extract Data]
    B --> C[Process Data]
    C --> D[Save Results]

    E[❌ Wrong Order] --> F[Save Results]
    F --> G[Process Data]
    G --> H[Extract Data]

    style E fill:#ffebee
    style F fill:#ffebee
    style G fill:#ffebee
    style H fill:#ffebee

Execution order fixes:

Problem	Cause	Solution
Async operations complete out of order	No proper waiting	Add synchronization nodes
Parallel branches interfere	Race conditions	Serialize critical operations
Dependencies not clear	Missing connections	Add explicit dependency connections
Timing issues	Network delays	Add wait/delay nodes

Missing or Invalid Data

Data validation checklist:

// Debug data flow between nodes
function debugDataFlow(nodeId, data) {
  console.log(`Node ${nodeId} received:`, {
    type: typeof data,
    value: data,
    isEmpty: data === null || data === undefined || data === '',
    isArray: Array.isArray(data),
    length: data?.length || 'N/A'
  });

  // Validate data structure
  if (typeof data === 'object' && data !== null) {
    console.log('Object keys:', Object.keys(data));
  }

  return data; // Pass through for next node
}

Common data flow issues:

Issue	Symptoms	Diagnostic	Solution
Null/undefined data	Empty results	Check source node success	Add validation and error handling
Wrong data structure	Type errors	Inspect data format	Add transformation nodes
Partial data	Missing fields	Check extraction completeness	Improve source data extraction
Corrupted data	Unexpected values	Validate data integrity	Add data cleaning steps

Node Configuration Issues

Parameter Configuration Problems

Symptoms:

Nodes execute but produce no output
Error messages about missing parameters
Unexpected node behavior

Configuration validation:

Node Type	Required Parameters	Common Mistakes	Fixes
Extraction nodes	CSS selectors, target elements	Wrong selectors	Test selectors in browser console
Processing nodes	Input data format, operations	Type mismatches	Verify input data structure
AI nodes	Prompts, model settings	Empty prompts	Provide clear, specific prompts
Output nodes	Destination, format	Missing destinations	Configure output targets

Parameter debugging:

// Validate node configuration
function validateNodeConfig(nodeType, config) {
  const validations = {
    extraction: {
      required: ['selector'],
      optional: ['attribute', 'multiple']
    },
    processing: {
      required: ['operation', 'inputData'],
      optional: ['options', 'format']
    },
    ai: {
      required: ['prompt', 'model'],
      optional: ['temperature', 'maxTokens']
    }
  };

  const nodeValidation = validations[nodeType];
  if (!nodeValidation) {
    return { valid: false, error: 'Unknown node type' };
  }

  // Check required parameters
  for (const param of nodeValidation.required) {
    if (!config[param]) {
      return { valid: false, error: `Missing required parameter: ${param}` };
    }
  }

  return { valid: true };
}

🔧 Advanced Connection Debugging

Data Flow Visualization

Create data flow diagrams:

graph TB
    subgraph "Data Flow Analysis"
        A[Web Page] -->|HTML Content| B[Extract Text]
        B -->|Raw Text| C[Clean Data]
        C -->|Cleaned Text| D[AI Analysis]
        D -->|Analysis Results| E[Format Output]
        E -->|Formatted Data| F[Save File]
    end

    subgraph "Debug Points"
        G[Debug: Raw HTML] --> B
        H[Debug: Extracted Text] --> C
        I[Debug: Cleaned Data] --> D
        J[Debug: AI Response] --> E
        K[Debug: Final Output] --> F
    end

Connection Testing Tools

Systematic connection testing:

// Test node connections
class ConnectionTester {
  constructor() {
    this.testResults = [];
  }

  testConnection(sourceNode, targetNode, testData) {
    const test = {
      source: sourceNode.id,
      target: targetNode.id,
      timestamp: new Date().toISOString(),
      success: false,
      error: null,
      data: null
    };

    try {
      // Simulate data flow
      const output = sourceNode.process(testData);
      const result = targetNode.process(output);

      test.success = true;
      test.data = result;
    } catch (e) {
      test.error = e.message;
    }

    this.testResults.push(test);
    return test;
  }

  generateReport() {
    const summary = {
      total: this.testResults.length,
      passed: this.testResults.filter(t => t.success).length,
      failed: this.testResults.filter(t => !t.success).length,
      details: this.testResults
    };

    console.table(summary.details);
    return summary;
  }
}

Workflow Validation

Comprehensive workflow validation:

// Validate entire workflow structure
function validateWorkflow(workflow) {
  const validation = {
    nodes: [],
    connections: [],
    executionOrder: [],
    issues: []
  };

  // Validate nodes
  workflow.nodes.forEach(node => {
    const nodeValidation = {
      id: node.id,
      type: node.type,
      configured: node.isConfigured(),
      hasInputs: node.inputs.length > 0,
      hasOutputs: node.outputs.length > 0
    };

    if (!nodeValidation.configured) {
      validation.issues.push(`Node ${node.id} is not properly configured`);
    }

    validation.nodes.push(nodeValidation);
  });

  // Validate connections
  workflow.connections.forEach(connection => {
    const connectionValidation = {
      from: connection.source,
      to: connection.target,
      valid: connection.isValid(),
      typeMatch: connection.typesMatch()
    };

    if (!connectionValidation.valid) {
      validation.issues.push(`Invalid connection from ${connection.source} to ${connection.target}`);
    }

    validation.connections.push(connectionValidation);
  });

  // Check for circular dependencies
  const hasCycles = detectCycles(workflow);
  if (hasCycles) {
    validation.issues.push('Workflow contains circular dependencies');
  }

  return validation;
}

🎯 Connection Best Practices

Robust Connection Design

Connection design principles:

Explicit dependencies - Make all data dependencies clear through connections
Type safety - Ensure compatible data types between connected nodes
Error propagation - Handle errors gracefully throughout the workflow
Data validation - Validate data at each connection point
Fallback handling - Provide alternative paths for failure scenarios

Example robust connection pattern:

graph TB
    A[Extract Data] --> B{Data Valid?}
    B -->|Yes| C[Process Data]
    B -->|No| D[Error Handler]
    C --> E{Processing Success?}
    E -->|Yes| F[Save Results]
    E -->|No| D
    D --> G[Log Error]
    D --> H[Notify User]

Data Transformation Strategies

Handle type mismatches:

// Universal data transformer
function transformData(data, targetType) {
  switch (targetType) {
    case 'string':
      if (typeof data === 'object') {
        return JSON.stringify(data);
      }
      return String(data);

    case 'number':
      if (typeof data === 'string') {
        const parsed = parseFloat(data);
        return isNaN(parsed) ? 0 : parsed;
      }
      return Number(data);

    case 'array':
      if (!Array.isArray(data)) {
        return [data];
      }
      return data;

    case 'object':
      if (typeof data === 'string') {
        try {
          return JSON.parse(data);
        } catch {
          return { value: data };
        }
      }
      return data;

    default:
      return data;
  }
}

Error Handling Patterns

Implement comprehensive error handling:

// Error handling wrapper for node connections
function safeNodeExecution(node, inputData) {
  const result = {
    success: false,
    data: null,
    error: null,
    nodeId: node.id,
    timestamp: new Date().toISOString()
  };

  try {
    // Validate input data
    if (!validateInputData(node, inputData)) {
      throw new Error('Invalid input data for node');
    }

    // Execute node
    result.data = node.execute(inputData);
    result.success = true;

  } catch (error) {
    result.error = {
      message: error.message,
      stack: error.stack,
      type: error.constructor.name
    };

    // Log error for debugging
    console.error(`Node ${node.id} execution failed:`, error);

    // Attempt recovery
    result.data = attemptErrorRecovery(node, inputData, error);
  }

  return result;
}

function attemptErrorRecovery(node, inputData, error) {
  // Implement recovery strategies based on error type
  if (error.message.includes('timeout')) {
    // Retry with longer timeout
    return node.executeWithTimeout(inputData, 30000);
  }

  if (error.message.includes('type')) {
    // Attempt type conversion
    const convertedData = transformData(inputData, node.expectedInputType);
    return node.execute(convertedData);
  }

  // Return safe default
  return null;
}

📊 Connection Performance Optimization

Efficient Data Flow

Optimize data passing:

// Efficient data flow patterns
class DataFlowOptimizer {
  constructor() {
    this.cache = new Map();
    this.metrics = {
      cacheHits: 0,
      cacheMisses: 0,
      totalTransfers: 0
    };
  }

  transferData(sourceId, targetId, data) {
    this.metrics.totalTransfers++;

    // Check cache for expensive computations
    const cacheKey = `${sourceId}-${targetId}-${this.hashData(data)}`;

    if (this.cache.has(cacheKey)) {
      this.metrics.cacheHits++;
      return this.cache.get(cacheKey);
    }

    this.metrics.cacheMisses++;

    // Process data transfer
    const result = this.processTransfer(data);

    // Cache result if beneficial
    if (this.shouldCache(data, result)) {
      this.cache.set(cacheKey, result);
    }

    return result;
  }

  hashData(data) {
    // Simple hash for caching
    return JSON.stringify(data).length;
  }

  shouldCache(input, output) {
    // Cache expensive operations
    return JSON.stringify(input).length > 1000 ||
           JSON.stringify(output).length > 1000;
  }

  getMetrics() {
    return {
      ...this.metrics,
      cacheEfficiency: this.metrics.cacheHits / this.metrics.totalTransfers
    };
  }
}

Connection Monitoring

Monitor connection health:

// Connection health monitoring
class ConnectionMonitor {
  constructor() {
    this.connections = new Map();
    this.alerts = [];
  }

  monitorConnection(connectionId, sourceId, targetId) {
    const connection = {
      id: connectionId,
      source: sourceId,
      target: targetId,
      transfers: 0,
      errors: 0,
      avgTransferTime: 0,
      lastTransfer: null,
      health: 'good'
    };

    this.connections.set(connectionId, connection);
  }

  recordTransfer(connectionId, success, duration, dataSize) {
    const connection = this.connections.get(connectionId);
    if (!connection) return;

    connection.transfers++;
    connection.lastTransfer = new Date();

    if (success) {
      // Update average transfer time
      connection.avgTransferTime =
        (connection.avgTransferTime * (connection.transfers - 1) + duration) /
        connection.transfers;
    } else {
      connection.errors++;
    }

    // Update health status
    this.updateConnectionHealth(connection);
  }

  updateConnectionHealth(connection) {
    const errorRate = connection.errors / connection.transfers;
    const isSlowTransfer = connection.avgTransferTime > 5000; // 5 seconds

    if (errorRate > 0.1 || isSlowTransfer) {
      connection.health = 'poor';
      this.alerts.push({
        connectionId: connection.id,
        issue: errorRate > 0.1 ? 'High error rate' : 'Slow transfers',
        timestamp: new Date()
      });
    } else if (errorRate > 0.05) {
      connection.health = 'fair';
    } else {
      connection.health = 'good';
    }
  }

  getHealthReport() {
    const connections = Array.from(this.connections.values());

    return {
      totalConnections: connections.length,
      healthDistribution: {
        good: connections.filter(c => c.health === 'good').length,
        fair: connections.filter(c => c.health === 'fair').length,
        poor: connections.filter(c => c.health === 'poor').length
      },
      recentAlerts: this.alerts.slice(-10),
      slowestConnections: connections
        .sort((a, b) => b.avgTransferTime - a.avgTransferTime)
        .slice(0, 5)
    };
  }
}

🆘 When Connections Still Don’t Work

Alternative Connection Methods

If standard connections fail:

Problem	Alternative Approach
Type incompatibility	Add transformation nodes
Timing issues	Use queue/buffer nodes
Complex data flow	Break into smaller workflows
Performance problems	Implement caching layers
Reliability issues	Add retry and fallback logic

Workflow Redesign Strategies

When to redesign workflows:

More than 20% of connections fail regularly
Execution time exceeds acceptable limits
Error rates are consistently high
Maintenance becomes difficult

Redesign approaches:

Simplify data flow - Reduce connection complexity
Add intermediate nodes - Break complex transformations into steps
Implement error boundaries - Isolate failure-prone sections
Use standard patterns - Follow proven workflow designs

Getting Help with Connection Issues

Information to provide when seeking help:

Workflow diagram showing all connections
Error messages and logs
Data samples at each connection point
Node configuration details
Expected vs. actual behavior
Steps already tried to resolve the issue

Useful debugging exports:

Workflow configuration JSON
Connection test results
Performance metrics
Error logs with timestamps