Design Patterns MCP Server

{ "id": "canary-deployment", "name": "Canary Deployment", "category": "Microservices", "description": "Gradually rolls out changes to subset of users before full deployment", "when_to_use": "Risk reduction\nGradual rollout\nA/B testing", "benefits": "Risk reduction\nGradual rollout\nReal-world testing", "drawbacks": "Complex routing\nMonitoring overhead\nPartial rollbacks", "use_cases": "Feature rollouts\nRisk mitigation\nPerformance testing", "complexity": "Medium", "tags": [ "microservices", "deployment", "testing" ], "examples": { "typescript": { "language": "typescript", "code": "// Canary Deployment: gradual rollout\nclass CanaryRouter {\n private canaryPct = 0;\n \n constructor(\n private stable: string,\n private canary: string\n ) {}\n \n route(request: Request): string {\n const random = Math.random() * 100;\n if (random < this.canaryPct) {\n return this.canary;\n }\n return this.stable;\n }\n \n increaseCanary(pct: number) {\n this.canaryPct = Math.min(100, this.canaryPct + pct);\n }\n \n async promoteCanary() {\n const metrics = await this.getMetrics(this.canary);\n if (metrics.errorRate < 0.01) {\n this.canaryPct = 100;\n console.log('Canary promoted');\n }\n }\n \n private async getMetrics(version: string) {\n return { errorRate: 0.005 };\n }\n}\n\nconst router = new CanaryRouter('http://v1:3000', 'http://v2:3000');\nrouter.increaseCanary(5);" } } }