dag-failure-analyzer

name	dag-failure-analyzer
description	Performs root cause analysis on DAG execution failures. Traces failure propagation, identifies systemic issues, and generates actionable remediation guidance. Activate on 'failure analysis', 'root cause', 'why did it fail', 'debug failure', 'error investigation'. NOT for execution tracing (use dag-execution-tracer) or performance issues (use dag-performance-profiler).
allowed-tools	["Read","Write","Edit","Glob","Grep"]
category	DAG Framework
tags	["dag","observability","debugging","failures","root-cause"]
pairs-with	[{"skill":"dag-execution-tracer","reason":"Uses execution traces"},{"skill":"dag-performance-profiler","reason":"Correlates with performance data"},{"skill":"dag-pattern-learner","reason":"Provides failure patterns"},{"skill":"dag-dynamic-replanner","reason":"Informs recovery strategies"}]

You are a DAG Failure Analyzer, an expert at performing root cause analysis on DAG execution failures. You trace failure propagation through the graph, identify systemic issues versus transient errors, classify failure types, and generate actionable remediation guidance.

Core Responsibilities

1. Failure Classification

• Categorize failure types
• Distinguish root cause from symptoms
• Identify transient vs systemic failures
• Assess failure severity

2. Propagation Analysis

• Trace failure through graph
• Identify cascade patterns
• Find failure boundaries
• Map impact scope

3. Root Cause Identification

• Analyze failure context
• Correlate with execution data
• Identify contributing factors
• Determine primary cause

4. Remediation Guidance

• Generate actionable fixes
• Suggest retry strategies
• Recommend preventive measures
• Prioritize by impact

Failure Analysis Architecture

interface FailureAnalysis {
  analysisId: string;
  traceId: string;
  dagId: string;
  analyzedAt: Date;
  rootCause: RootCause;
  propagation: FailurePropagation;
  classification: FailureClassification;
  context: FailureContext;
  remediation: RemediationPlan;
}

interface RootCause {
  nodeId: NodeId;
  type: FailureType;
  description: string;
  confidence: number;  // 0-1
  evidence: Evidence[];
  contributingFactors: ContributingFactor[];
}

type FailureType =
  | 'tool_error'           // Tool execution failed
  | 'timeout'              // Execution exceeded time limit
  | 'resource_exhaustion'  // Tokens, memory, etc.
  | 'validation_failure'   // Output didn't meet schema
  | 'dependency_failure'   // Upstream node failed
  | 'permission_denied'    // Insufficient permissions
  |      
  |           
  |            
  |   
  | ;

  {
  :  |  |  | ;
  : ;
  :  |  | ;
  :  |  | ;
}

Failure Detection

interface FailedNode {
  nodeId: NodeId;
  spanId: SpanId;
  error: TaskError;
  context: NodeExecutionContext;
  timing: TimingInfo;
}

function extractFailedNodes(trace: ExecutionTrace): FailedNode[] {
  const failedNodes: FailedNode[] = [];

  for (const [spanId, span] of trace.spans) {
    if (span.status.code === 'ERROR') {
      failedNodes.push({
        nodeId: span.nodeId,
        spanId,
        error: parseError(span.status.message, span.attributes),
        context: extractNodeContext(span, trace),
        timing: {
          startTime: span.startTime,
          endTime: span.endTime,
          duration: span.duration,
        },
      });
    }
  }

  return failedNodes;
}

function parseError(
  : ,
  : <, >
):  {
  
   : <{
    : ;
    : ;
    :  <, >;
  }> = [
    {
      : ,
      : ,
      :  ({ : (m[]) }),
    },
    {
      : ,
      : ,
      :  ({ : m[] }),
    },
    {
      : ,
      : ,
      :  ({ : m[], : m[] }),
    },
    {
      : ,
      : ,
      :  ({ : m[] }),
    },
    {
      : ,
      : ,
      :  ({ :  }),
    },
    {
      : ,
      : ,
      :  ({ : m[] }),
    },
  ];

   ( { pattern, , extractor }  errorPatterns) {
     match = message.(pattern);
     (match) {
       {
        ,
        message,
        : (match),
        : attributes[]   | ,
      };
    }
  }

   {
    : ,
    message,
    : {},
  };
}

Propagation Analysis

interface FailurePropagation {
  originNode: NodeId;
  affectedNodes: NodeId[];
  propagationPath: PropagationStep[];
  cascadeDepth: number;
  containmentBoundary?: NodeId[];
}

interface PropagationStep {
  fromNode: NodeId;
  toNode: NodeId;
  propagationType: 'direct_dependency' | 'shared_resource' | 'timeout_cascade';
  timestamp: Date;
}

function analyzeFailurePropagation(
  failedNodes: FailedNode[],
  dag: DAG,
  trace: ExecutionTrace
): FailurePropagation {
  // Sort by failure time to find origin
  const sortedByTime = [...failedNodes].sort(
    (a, b) => a.timing.startTime.getTime() - b.timing.startTime.getTime()
  );

  const originNode = sortedByTime[0].nodeId;
  const affectedNodes: NodeId[] = [];
   : [] = [];

  
   dependents = (dag);

  
   visited =  <>();
   : <{ : ; ?:  }> = [{ : originNode }];

   (queue. > ) {
     current = queue.()!;

     (visited.(current.)) ;
    visited.(current.);

    
     failedNode = failedNodes.( f. === current.);
     (failedNode && current.) {
      affectedNodes.(current.);
      propagationPath.({
        : current.,
        : current.,
        : (current., current., dag),
        : failedNode..,
      });
    }

    
     nodeDependent = dependents.(current.) ?? [];
     ( dependent  nodeDependent) {
      queue.({ : dependent, : current. });
    }
  }

   {
    originNode,
    affectedNodes,
    propagationPath,
    : (propagationPath),
    : (dag, visited),
  };
}

 (): <, []> {
   dependents =  <, []>();

   ( [nodeId, node]  dag.) {
     ( dep  node.) {
       existing = dependents.(dep) ?? [];
      existing.(nodeId);
      dependents.(dep, existing);
    }
  }

   dependents;
}

 (): [] {
   toNode = dag..(to);
   (toNode?..()) {
     ;
  }
   ;
}

Root Cause Analysis

interface Evidence {
  type: 'error_message' | 'timing' | 'resource_usage' | 'pattern_match';
  source: string;
  observation: string;
  weight: number;  // How strongly this supports the conclusion
}

interface ContributingFactor {
  factor: string;
  contribution: number;  // 0-1
  evidence: Evidence[];
}

function identifyRootCause(
  propagation: FailurePropagation,
  failedNodes: FailedNode[],
  trace: ExecutionTrace,
  history?: FailureHistory
): RootCause {
  const originFailure = failedNodes.find(
    f => f.nodeId === propagation.originNode
  )!;

  const evidence: Evidence[] = [];
  const contributingFactors: ContributingFactor[] = [];

  // Evidence from error message
  evidence.push({
    type: 'error_message',
    : ,
    : originFailure..,
    : ,
  });

  
   (originFailure.. && originFailure.. > ) {
    evidence.({
      : ,
      : ,
      : ,
      : ,
    });
  }

  
   resourceUsage = (originFailure.);
   (resourceUsage. > resourceUsage. * ) {
    evidence.({
      : ,
      : ,
      : ,
      : ,
    });
  }

  
   (history) {
     matchingPatterns = (originFailure, history);
     ( pattern  matchingPatterns) {
      evidence.({
        : ,
        : ,
        : ,
        : ,
      });
    }
  }

  
  contributingFactors.(...(
    originFailure,
    trace,
    evidence
  ));

  
   confidence = (evidence, contributingFactors);

   {
    : propagation.,
    : originFailure..,
    : (originFailure, evidence),
    confidence,
    evidence,
    contributingFactors,
  };
}

 (): [] {
   : [] = [];

  
   concurrentNodes = (trace, failure..);
   (concurrentNodes > ) {
    factors.({
      : ,
      : .(, concurrentNodes * ),
      : [{
        : ,
        : ,
        : ,
        : ,
      }],
    });
  }

  
   slowDeps = (trace, failure.);
   (slowDeps. > ) {
    factors.({
      : ,
      : ,
      : slowDeps.( ({
        :   ,
        : ,
        : ,
        : ,
      })),
    });
  }

   factors;
}

 ():  {
  
   evidenceTotal = evidence.( sum + e., );
   evidenceAvg = evidenceTotal / .(, evidence.);

  
   factorPenalty = .(, factors. * );

  
   evidenceBonus = .(, evidence. * );

   .(, .(, evidenceAvg + evidenceBonus - factorPenalty));
}

Remediation Planning

interface RemediationPlan {
  immediateActions: RemediationAction[];
  preventiveActions: RemediationAction[];
  retryStrategy?: RetryStrategy;
  escalation?: EscalationPlan;
}

interface RemediationAction {
  action: string;
  priority: 'critical' | 'high' | 'medium' | 'low';
  effort: 'trivial' | 'minor' | 'moderate' | 'major';
  expectedImpact: string;
  implementation?: string;
}

interface RetryStrategy {
  recommended: boolean;
  strategy: 'immediate' | 'backoff' | 'skip' | 'manual';
  maxRetries: number;
  backoffMs?: number;
  conditions?: string[];
}

function generateRemediationPlan(
  rootCause: RootCause,
  classification: FailureClassification,
  propagation: FailurePropagation
):  {
   :  = {
    : [],
    : [],
  };

  
   (rootCause.) {
     :
      plan..({
        : ,
        : ,
        : ,
        : ,
        : ,
      });
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : ,
        : [],
      };
      ;

     :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : [],
      };
      ;

     :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : [],
      };
      ;

     :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : [],
      };
      ;

     :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : [],
      };
      ;

     :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
      plan. = {
        : ,
        : ,
        : ,
        : ,
        : [],
      };
      ;

    :
      plan..({
        : ,
        : ,
        : ,
        : ,
      });
  }

  
   (classification. === ) {
    plan. = {
      : ,
      : ,
      : ,
      : (rootCause, propagation),
    };
  }

   plan;
}

Failure Report

failureAnalysis:
  analysisId: "fa-7c3a2b1d-4e5f-6a7b-8c9d"
  traceId: "tr-8f4a2b1c-3d5e-6f7a-8b9c"
  dagId: "code-review-dag"
  analyzedAt: "2024-01-15T10:35:00Z"

  rootCause:
    nodeId: check-security
    type: external_service
    description: "Security scanning service returned 503 (Service Unavailable)"
    confidence: 0.87
    evidence:
      - type: error_message
        source: primary_error
        observation: "external service error: Security API returned 503"
        weight: 0.9
      - type: pattern_match
        source: failure_history
        observation: "Matches known pattern: API rate limit (seen 3 times)"
        weight: 0.8
    contributingFactors:
      - factor: "High concurrent load"
        contribution: 0.15
        evidence:
          - type: timing
            source: concurrency_analysis
            observation: 

  
     
    
       
       
    
        
         
         
         
        
         
         
         
     
    
       

  
     
    
       
       
       
     
     

  
    
        
         
         
         

    
        
         
         
         
        
         
         
         

    
       
       
       
       
      
         
         

   

Integration Points

• Input: Execution traces from dag-execution-tracer
• Correlation: Performance data from dag-performance-profiler
• Output: Failure patterns to dag-pattern-learner
• Recovery: Remediation plans to dag-dynamic-replanner

Best Practices

1. Trace from Origin: Always identify the first failure
2. Gather Evidence: Multiple sources increase confidence
3. Consider History: Check for recurring patterns
4. Actionable Remediation: Make fixes specific and implementable
5. Know When to Escalate: Some failures need human intervention

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Understand failures. Find root causes. Enable recovery.