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Non-Functional Requirements

This document outlines the non-functional requirements (NFRs) for GripDay, a B2B marketing automation platform built with microservices architecture on Kubernetes. These requirements define the quality attributes, constraints, and operational characteristics that the system must satisfy.

🎯 Performance Requirements

Response Time Requirements

ComponentRequirementTargetMeasurement
API Response TimeAll REST API endpoints< 200ms (95th percentile)Application Performance Monitoring
Page Load TimeFrontend application< 1s (initial load)Browser performance metrics
Database Query TimePostgreSQL queries< 100ms (95th percentile)Database monitoring
Email Delivery TimeEmail queue processing< 30s (from trigger to send)Message queue metrics
Campaign ExecutionWorkflow processing< 5s (per step)Campaign engine metrics
Form SubmissionForm processing< 500msForm analytics
Search OperationsElasticsearch queries< 300msSearch performance metrics

Throughput Requirements

ComponentRequirementTargetMeasurement
API RequestsConcurrent API calls1,000 requests/secondLoad testing
Email SendingBulk email processing10,000 emails/hourEmail service metrics
Contact ImportCSV import processing100,000 contacts/hourImport service metrics
Event ProcessingKafka message throughput50,000 events/secondKafka metrics
Form SubmissionsConcurrent form processing500 submissions/secondForm service metrics
Campaign ProcessingWorkflow execution1,000 contacts/minuteCampaign metrics

Scalability Requirements

AspectRequirementTargetImplementation
Horizontal ScalingMicroservices auto-scaling2-50 pods per serviceKubernetes HPA
Database ScalingRead replicasUp to 5 read replicas per servicePostgreSQL clustering
Cache ScalingRedis clusterUp to 10 nodesRedis Cluster
Storage ScalingFile storageUnlimited (cloud-based)MinIO/S3
User CapacityConcurrent users10,000 active usersLoad balancing
Data VolumeContact storage10 million contactsDatabase partitioning

🔒 Security Requirements

Authentication & Authorization

RequirementSpecificationImplementation
Authentication MethodJWT-based stateless authenticationSpring Security 6 with JWT
Token ExpirationAccess tokens: 15 minutes, Refresh tokens: 7 daysJWT configuration
Password PolicyMin 8 chars, uppercase, lowercase, number, special charBCrypt hashing
Multi-Factor AuthenticationTOTP-based 2FA supportOptional for enterprise
Role-Based Access ControlGranular permissions per microserviceSpring Security RBAC
Service-to-Service AuthJWT propagation between servicesAPI Gateway integration
Session ManagementStateless with Redis for session dataRedis-based sessions

Data Security

RequirementSpecificationImplementation
Data Encryption at RestAES-256 encryption for sensitive dataDatabase encryption
Data Encryption in TransitTLS 1.3 for all communicationsIstio mTLS
PII ProtectionEncryption of personally identifiable informationApplication-level encryption
Database SecurityEncrypted connections and access controlsPostgreSQL SSL
API SecurityRate limiting and request validationAPI Gateway policies
Secret ManagementKubernetes secrets with rotationExternal Secrets Operator

Infrastructure Security

RequirementSpecificationImplementation
Pod Security StandardsRestricted security profileKubernetes PSS
Network PoliciesDeny-all default with explicit allow rulesKubernetes Network Policies
Service Mesh SecurityAutomatic mTLS between servicesIstio security policies
Image SecurityContainer image scanning and signingCI/CD security scanning
RBACLeast-privilege access for all servicesKubernetes RBAC
Admission ControllersPolicy enforcement at deploymentOPA Gatekeeper

🔄 Reliability Requirements

Availability Requirements

ComponentRequirementTargetImplementation
System UptimeOverall platform availability99.9% (43 minutes downtime/month)Multi-zone deployment
API GatewayGateway availability99.95%Load balancing with health checks
Database AvailabilityPostgreSQL clusters99.9%High availability with failover
Message QueueKafka cluster availability99.9%Multi-broker setup
Cache AvailabilityRedis cluster99.5%Redis Cluster with failover
Email ServiceEmail delivery service99.5%Multiple SMTP providers

Fault Tolerance

RequirementSpecificationImplementation
Circuit BreakersPrevent cascade failuresResilience4j integration
Retry MechanismsAutomatic retry with exponential backoffSpring Retry
Graceful DegradationPartial functionality during failuresFeature flags
Health ChecksLiveness, readiness, and startup probesKubernetes health checks
FailoverAutomatic failover for critical servicesKubernetes deployment strategies
Data BackupAutomated backup with point-in-time recoveryVelero + database backups

Recovery Requirements

AspectRequirementTargetImplementation
Recovery Time Objective (RTO)Maximum downtime15 minutesAutomated recovery
Recovery Point Objective (RPO)Maximum data loss5 minutesContinuous backup
Backup FrequencyDatabase backupsEvery 4 hoursAutomated backup jobs
Backup RetentionBackup storage duration30 daysBackup lifecycle policies
Disaster RecoveryCross-region recovery4 hoursMulti-region deployment

📊 Monitoring & Observability Requirements

Metrics Collection

CategoryRequirementImplementation
Application MetricsBusiness and technical metricsPrometheus + Spring Boot Actuator
Infrastructure MetricsKubernetes and system metricsPrometheus + Node Exporter
Custom MetricsBusiness-specific KPIsCustom Prometheus metrics
Real-time DashboardsLive monitoring dashboardsGrafana dashboards
AlertingIntelligent alerting with escalationAlertmanager + PagerDuty

Logging Requirements

AspectRequirementImplementation
Centralized LoggingAll logs in central locationELK Stack (Elasticsearch, Logstash, Kibana)
Log RetentionLog storage duration90 days for application logs
Log LevelsStructured logging with levelsLogback with JSON format
Log CorrelationTrace requests across servicesOpenTelemetry trace IDs
Log SecuritySensitive data maskingLog sanitization

Distributed Tracing

RequirementSpecificationImplementation
Request TracingEnd-to-end request trackingJaeger with OpenTelemetry
Service DependenciesService interaction mappingService mesh observability
Performance AnalysisLatency and bottleneck identificationDistributed tracing analysis
Error TrackingError propagation across servicesTrace error correlation

🚀 Deployment & Operations Requirements

Kubernetes Requirements

AspectRequirementImplementation
Container OrchestrationKubernetes-native deploymentKubernetes 1.28+
Service MeshTraffic management and securityIstio service mesh
Package ManagementTemplated deploymentsHelm charts
GitOps DeploymentDeclarative deployment pipelineArgoCD
Auto-scalingHorizontal and vertical scalingHPA, VPA, Cluster Autoscaler
Resource ManagementResource limits and requestsKubernetes resource quotas

CI/CD Requirements

StageRequirementImplementation
Build PipelineAutomated build and testGitHub Actions
Code QualityCode coverage > 80%SonarQube integration
Security ScanningVulnerability scanningSnyk/Trivy integration
Deployment StrategyBlue-green deploymentsKubernetes deployment strategies
Rollback CapabilityAutomated rollback on failureHelm rollback
Environment PromotionDev → Staging → ProductionGitOps workflow

Backup & Disaster Recovery

RequirementSpecificationImplementation
Cluster BackupFull cluster state backupVelero
Database BackupPoint-in-time recoveryPostgreSQL continuous archiving
Configuration BackupInfrastructure as codeGit repository
Cross-region ReplicationMulti-region deploymentCloud provider replication
Recovery TestingRegular disaster recovery drillsMonthly DR tests

🔧 Maintainability Requirements

Code Quality

AspectRequirementImplementation
Code CoverageMinimum test coverage80% unit test coverage
Code StandardsConsistent coding standardsCheckstyle, ESLint, Prettier
DocumentationComprehensive documentationJavaDoc, OpenAPI specs
Code ReviewsMandatory peer reviewsGitHub PR reviews
Static AnalysisAutomated code analysisSonarQube

Architecture Quality

RequirementSpecificationImplementation
Service IndependenceLoosely coupled microservicesDomain-driven design
API VersioningBackward-compatible API evolutionSemantic versioning
Database MigrationsVersion-controlled schema changesLiquibase migrations
Configuration ManagementExternalized configurationKubernetes ConfigMaps
Dependency ManagementControlled dependency updatesDependabot

🌐 Usability Requirements

User Experience

AspectRequirementTarget
Page Load TimeInitial page load< 1 second
Interface ResponsivenessUI interaction response< 100ms
Mobile ResponsivenessMobile device support100% responsive design
Browser CompatibilitySupported browsersChrome, Firefox, Safari, Edge (latest 2 versions)
AccessibilityWCAG complianceWCAG 2.1 AA compliance
User OnboardingTime to first value< 5 minutes

Internationalization

RequirementSpecificationImplementation
Multi-language SupportUI localizationReact i18n
Time Zone SupportGlobal time zone handlingUTC with local conversion
Currency SupportMulti-currency pricingConfigurable currency settings
Date/Time FormatsLocale-specific formattingInternationalization libraries

📈 Capacity Requirements

Data Storage

Data TypeEstimated VolumeGrowth RateStorage Requirements
Contact Data10M contacts20% annually100GB initial, 20GB/year
Email Data100M emails50% annually500GB initial, 250GB/year
Campaign Data1M campaigns30% annually50GB initial, 15GB/year
Analytics DataEvent streams100% annually1TB initial, 1TB/year
File StorageAssets and uploads40% annually200GB initial, 80GB/year

Resource Requirements

EnvironmentCPUMemoryStorageNetwork
Development8 cores16GB RAM100GB SSD1Gbps
Staging16 cores32GB RAM500GB SSD1Gbps
Production64 cores128GB RAM2TB SSD10Gbps
Per Microservice0.5-2 cores1-4GB RAM10-50GB100Mbps

🔍 Compliance Requirements

Data Protection

RegulationRequirementImplementation
GDPREU data protection complianceData encryption, right to deletion
CCPACalifornia privacy complianceData transparency, opt-out mechanisms
SOC 2Security and availability controlsAudit logging, access controls
ISO 27001Information security managementSecurity policies and procedures

Industry Standards

StandardRequirementImplementation
OAuth 2.0Secure authorizationSpring Security OAuth2
OpenAPI 3.0API documentation standardSwagger/OpenAPI specs
JSON Web TokensSecure token formatJWT implementation
REST APIRESTful service designSpring Boot REST controllers

🎛️ Configuration Requirements

Environment Configuration

EnvironmentConfigurationManagement
DevelopmentLocal development settingsDocker Compose
StagingPre-production testingKubernetes ConfigMaps
ProductionProduction-ready settingsKubernetes Secrets
Feature FlagsRuntime feature togglesExternal feature flag service

Service Configuration

ServiceConfiguration NeedsImplementation
DatabaseConnection pools, timeoutsSpring Boot configuration
CacheTTL, eviction policiesRedis configuration
Message QueueTopics, partitions, retentionKafka configuration
SecurityJWT settings, CORS policiesSpring Security configuration

📋 Testing Requirements

Test Coverage

Test TypeCoverage RequirementImplementation
Unit Tests80% code coverageJUnit 5, Mockito
Integration TestsCritical path coverageTestcontainers
End-to-End TestsUser journey coverageCypress/Playwright
Performance TestsLoad and stress testingJMeter/K6
Security TestsVulnerability scanningOWASP ZAP

Test Automation

AspectRequirementImplementation
Continuous TestingAutomated test executionCI/CD pipeline integration
Test Data ManagementIsolated test dataDatabase seeding
Test EnvironmentDedicated test infrastructureKubernetes test namespaces
Contract TestingAPI contract validationPact testing

🚨 Error Handling Requirements

Error Response Standards

Error TypeResponse FormatHTTP Status
Validation ErrorsStructured error messages400 Bad Request
Authentication ErrorsSecurity-safe messages401 Unauthorized
Authorization ErrorsAccess denied messages403 Forbidden
Resource Not FoundResource identification404 Not Found
Server ErrorsGeneric error messages500 Internal Server Error

Error Recovery

ScenarioRecovery StrategyImplementation
Service UnavailableCircuit breaker activationResilience4j
Database ConnectionConnection pool retryHikariCP retry
Message Queue FailureDead letter queueKafka DLQ
External API FailureFallback mechanismsHystrix patterns

📊 Success Metrics

Key Performance Indicators (KPIs)

MetricTargetMeasurement Method
System Uptime99.9%Monitoring dashboards
API Response Time< 200ms (95th percentile)APM tools
Error Rate< 0.1%Error tracking
Deployment FrequencyDailyCI/CD metrics
Mean Time to Recovery< 15 minutesIncident tracking
Customer Satisfaction> 4.5/5User feedback

Operational Metrics

MetricTargetMonitoring
Pod Restart Rate< 1 per day per serviceKubernetes metrics
Resource Utilization60-80% CPU/MemoryResource monitoring
Backup Success Rate100%Backup monitoring
Security Scan Pass Rate100%Security pipeline
Test Pass Rate> 95%CI/CD reporting

🔄 Review and Updates

Document Maintenance

  • Review Frequency: Quarterly
  • Update Triggers: Architecture changes, new requirements, performance issues
  • Approval Process: Technical lead and stakeholder review
  • Version Control: Git-based versioning with change tracking

Compliance Monitoring

  • Regular Audits: Monthly compliance checks
  • Performance Reviews: Weekly performance metric analysis
  • Security Assessments: Quarterly security reviews
  • Capacity Planning: Bi-annual capacity assessments

This document serves as the definitive guide for non-functional requirements and should be referenced during all architectural decisions, implementation planning, and system operations.

Released under the MIT License.