track_cold_starts

Instructions

Implementation Reference

• index.js:64-82 (registration)

  Registration of the track_cold_starts tool in the ListTools response, including name, description, and input schema

  {
    name: 'track_cold_starts',
    description: 'Track and analyze cold start patterns for Lambda functions',
    inputSchema: {
      type: 'object',
      properties: {
        functionName: {
          type: 'string',
          description: 'Name of the Lambda function'
        },
        timeRange: {
          type: 'string',
          enum: ['1h', '6h', '24h', '7d'],
          description: 'Time range for cold start analysis (default: 24h)'
        }
      },
      required: ['functionName']
    }
  },

• index.js:67-81 (schema)

  Input schema definition for track_cold_starts tool parameters

  inputSchema: {
    type: 'object',
    properties: {
      functionName: {
        type: 'string',
        description: 'Name of the Lambda function'
      },
      timeRange: {
        type: 'string',
        enum: ['1h', '6h', '24h', '7d'],
        description: 'Time range for cold start analysis (default: 24h)'
      }
    },
    required: ['functionName']
  }

• index.js:286-315 (handler)

  Tool handler method that processes tool arguments, delegates to ColdStartTracker for analysis, formats the markdown response, and returns it

  async trackColdStarts(args) {
    const { functionName, timeRange = '24h' } = args;
    
    const coldStartData = await this.coldStartTracker.trackColdStarts(
      functionName, 
      timeRange
    );
  
    return {
      content: [
        {
          type: 'text',
          text: `# Cold Start Analysis: ${functionName}\n\n` +
                `## Cold Start Statistics\n` +
                `- **Total Cold Starts**: ${coldStartData.total}\n` +
                `- **Cold Start Rate**: ${coldStartData.rate}%\n` +
                `- **Average Cold Start Duration**: ${coldStartData.avgDuration}ms\n` +
                `- **Longest Cold Start**: ${coldStartData.maxDuration}ms\n\n` +
                `## Cold Start Patterns\n` +
                `- **Peak Hours**: ${coldStartData.peakHours.join(', ')}\n` +
                `- **Frequency**: ${coldStartData.frequency}\n` +
                `- **Triggers**: ${coldStartData.triggers.join(', ')}\n\n` +
                `## Optimization Opportunities\n` +
                `${coldStartData.recommendations.map(rec => `- ${rec}`).join('\n')}\n\n` +
                `## Timeline\n` +
                `${this.formatColdStartTimeline(coldStartData.timeline)}`
        }
      ]
    };
  }

• src/cold-start-tracker.js:14-49 (helper)

  Core helper function in ColdStartTracker that fetches cold start events from CloudWatch Logs, performs analysis on patterns, statistics, and generates recommendations

  async trackColdStarts(functionName, timeRange) {
    const timeRangeMs = this.parseTimeRange(timeRange);
    const endTime = new Date();
    const startTime = new Date(endTime.getTime() - timeRangeMs);
    
    const logGroupName = `/aws/lambda/${functionName}`;
    
    try {
      // Get cold start events
      const coldStartEvents = await this.getColdStartEvents(logGroupName, startTime, endTime);
      
      // Get all invocation events for comparison
      const allInvocations = await this.getAllInvocations(logGroupName, startTime, endTime);
      
      // Analyze patterns
      const analysis = this.analyzeColdStartPatterns(coldStartEvents, allInvocations, timeRange);
      
      return {
        total: coldStartEvents.length,
        rate: this.calculateColdStartRate(coldStartEvents.length, allInvocations.length),
        avgDuration: analysis.avgDuration,
        maxDuration: analysis.maxDuration,
        minDuration: analysis.minDuration,
        peakHours: analysis.peakHours,
        frequency: analysis.frequency,
        triggers: analysis.triggers,
        recommendations: this.generateRecommendations(analysis),
        timeline: this.createTimeline(coldStartEvents, timeRange),
        patterns: analysis.patterns,
        statistics: analysis.statistics
      };
    } catch (error) {
      console.error('Error tracking cold starts:', error);
      return this.getEmptyResult();
    }
  }