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API Gateway Issues, Incidents, and Mitigation Strategies #

Performance & Scalability Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Throughput bottlenecksS: E-commerce platform during holiday sale
T: Process 10x normal API traffic
A: API gateway became bottleneck despite backend scaling
R: Degraded user experience and lost sales
- Single-instance deployment
- Vertical-only scaling
- Synchronous processing
- Resource contention
- Inefficient routing logic
Horizontal Gateway Scaling Pattern
with stateless design and load distribution
- Amazon API Gateway throttling during Prime Day
- Shopify API limits during Black Friday
- Kong Gateway performance incidents
Connection pooling exhaustionS: Microservice platform handling user requests
T: Maintain consistent response times under load
A: Connection pools to backends exhausted
R: Cascading timeouts and service degradation
- Undersized connection pools
- Long-lived connections
- Missing connection management
- Backend slowdowns
- Aggressive timeout settings
Adaptive Connection Management Pattern
with dynamic pool sizing and circuit breakers
- Netflix API gateway connection limitations
- AWS API Gateway 504 errors under load
- Azure APIM connection timeout incidents
Memory leaksS: High-volume payment processing gateway
T: Process transactions reliably over time
A: Memory leaks in custom plugins caused progressive degradation
R: Regular restarts required to maintain performance
- Custom plugin issues
- Missing garbage collection
- Resource cleanup failures
- Long-running request handling
- Improper caching implementation
Resource Lifecycle Management Pattern
with memory profiling and automated scaling
- Kong Gateway memory issues with custom plugins
- Zuul memory leak incidents
- Spring Cloud Gateway resource exhaustion
Latency spikesS: Financial services API platform
T: Maintain consistent low-latency responses
A: Periodic JVM garbage collection caused visible spikes
R: Intermittent transaction timeouts affecting user experience
- Garbage collection pauses
- Synchronous processing
- No request buffering
- Lack of resource isolation
- Monolithic gateway instances
Predictable Latency Pattern
with resource isolation and latency budgeting
- Apigee latency spikes during peak loads
- Kong Gateway p99 latency degradation
- AWS API Gateway cold start latency

Reliability & Resilience Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Cascading failuresS: Microservice ecosystem during partial outage
T: Maintain overall system availability
A: Failing service caused gateway thread pool saturation
R: Complete system unavailability despite partial backend issue
- Missing circuit breakers
- Timeout misconfigurations
- Synchronous call chains
- Shared resource pools
- No bulkhead isolation
Circuit Breaker Pattern
with service isolation and graceful degradation
- Netflix API gateway failure cascade incidents
- Monzo banking outage from gateway saturation
- Heroku API gateway failure amplification
Single point of failureS: Global SaaS platform
T: Ensure continuous API availability
A: Gateway configuration database failure caused global outage
R: Complete platform unavailability despite healthy services
- Centralized configuration store
- Single control plane
- Tight coupling to management systems
- Stateful gateway design
- Lack of failover automation
Multi-region Gateway Pattern
with decentralized configuration and autonomous operation
- Cloudflare API gateway global outage
- Fastly configuration service impact
- Akamai global gateway disruption
Configuration propagation failuresS: Multi-region API platform
T: Deploy security patch to all gateway instances
A: Configuration changes failed to propagate to some regions
R: Inconsistent security enforcement and regional failures
- Manual configuration processes
- Asynchronous config updates
- Missing consistency verification
- Region-specific settings
- Push-based propagation
Consistent Configuration Pattern
with versioned configs and atomic propagation
- Azure APIM configuration inconsistencies
- Traefik dynamic configuration issues
- Amazon API Gateway deployment failures
Improper failoverS: Payment processing platform
T: Automatically recover from zone failure
A: Failover mechanism failed, routing to unavailable instances
R: Extended payment processing outage despite redundant capacity
- Inadequate health checking
- Single health check type
- Aggressive failover thresholds
- Incomplete failover testing
- Missing cross-region verification
Active Monitoring Failover Pattern
with comprehensive health checking
- Payment gateway failover failures
- Kong Gateway health check limitations
- AWS API Gateway zone failover incidents

Security Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Authentication bypassS: Multi-tenant SaaS API platform
T: Ensure proper authentication for all API calls
A: Inconsistent auth enforcement allowed bypass paths
R: Unauthorized access to customer data
- Inconsistent auth configuration
- Path-based rule exceptions
- Direct endpoint exposure
- Multiple auth methods
- Gateway bypass opportunities
Defense-in-Depth Authentication Pattern
with layered auth enforcement
- Auth0 configuration bypass incidents
- API gateway mis-configuration exposures
- OAuth bypass vulnerabilities
Token validation failuresS: Financial services API
T: Validate JWT tokens for secure access
A: Improper signature validation allowed forged tokens
R: Unauthorized transaction processing and potential fraud
- Missing key rotation
- Weak validation algorithms
- Inadequate signature checking
- Improper key management
- Algorithm confusion attacks
Robust Token Validation Pattern
with explicit algorithm verification
- JWT validation vulnerabilities (CVE-2018-0114)
- API gateway token forgery incidents
- Kong Gateway JWT plugin issues
Rate limiting bypassS: Public API service with tiered access
T: Enforce usage limits per customer
A: Distributed clients circumvented rate limiting
R: Service degradation and unfair resource allocation
- IP-based rate limiting
- Missing client identification
- Per-instance rate limits
- Lack of global rate limiting
- Token sharing/pooling
Distributed Rate Limiting Pattern
with global counter coordination
- API abuse incidents on public APIs
- GitHub API rate limit evasion
- Redis rate limit counter saturation
Insufficient loggingS: Financial compliance-regulated API
T: Track all access for audit purposes
A: Critical request metadata missing from gateway logs
R: Inability to investigate security incidents
- Minimalist logging defaults
- Performance-optimized logging
- Missing security context
- Incomplete request capture
- Storage-constrained logging
Comprehensive Audit Logging Pattern
with context-rich security logging
- PCI compliance failures from insufficient logs
- GDPR violation investigation challenges
- Forensic gaps in security incidents

Traffic Management Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Routing rule conflictsS: Microservice platform with complex routing
T: Implement new routing rules for feature release
A: Conflicting rules created unpredictable request routing
R: Traffic sent to incorrect services causing errors
- Manual rule management
- Missing rule verification
- Order-dependent rules
- Pattern overlap conflicts
- Multiple rule authors
Verified Routing Pattern
with automated rule validation and conflict detection
- Istio routing rule conflicts
- Kong Gateway route priority issues
- Traefik path precedence problems
Canary deployment failuresS: E-commerce checkout flow update
T: Safely deploy new API version to subset of users
A: Traffic splitting logic failed to respect session affinity
R: Inconsistent experience with mid-session version switching
- Missing session awareness
- Probabilistic routing only
- Inadequate canary criteria
- Simplistic health checks
- Incomplete canary metrics
Contextual Canary Pattern
with session affinity and comprehensive metrics
- Progressive delivery failures
- Ambassador API Gateway canary issues
- A/B testing session consistency problems
Quota management issuesS: Multi-tenant API platform with service tiers
T: Enforce different quotas for various subscription levels
A: Quota counters reset prematurely during counter failure
R: Enterprise customers exceeded quotas, impacting system stability
- Local-only quota tracking
- Fixed time window implementation
- Counter persistence issues
- Quota reset timing errors
- Missing quota safety mechanisms
Resilient Quota Pattern
with durable tracking and degraded operation modes
- API quota leakage incidents
- AWS API Gateway quota implementation challenges
- Azure APIM quota counter reset problems
Load balancing imbalanceS: Kubernetes-based API platform
T: Distribute load evenly across service instances
A: Round-robin distribution caused hot spots with varied request costs
R: Some instances overloaded while others underutilized
- Simplistic load balancing
- Request cost blindness
- Missing backend feedback
- Lack of adaptive balancing
- Connection-based (not request-based) balancing
Adaptive Load Balancing Pattern
with cost-aware distribution and backend telemetry
- Service mesh load imbalance issues
- Kong Gateway backend hotspots
- NGINX Plus load balancing distribution skew

Integration & Interoperability Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Protocol translation errorsS: Legacy system integration project
T: Connect SOAP backend to modern REST API
A: Gateway protocol translation introduced subtle data errors
R: Inconsistent data processing and invalid transactions
- Simplified data mapping
- Missing schema validation
- Character encoding issues
- Default transformation rules
- Incomplete protocol understanding
Validated Transformation Pattern
with comprehensive schema enforcement
- SOAP-to-REST translation failures
- Character encoding corruption in gateways
- JSON-XML conversion data loss
Backend contract changesS: Microservice ecosystem continuous deployment
T: Maintain gateway compatibility during backend changes
A: Undocumented backend API changes broke gateway mappings
R: Customer-facing errors after seemingly unrelated update
- Missing API contracts
- Independent deployment cycles
- Implicit interface assumptions
- Inadequate integration testing
- Schema evolution issues
API Contract Pattern
with formal specifications and compatibility verification
- Breaking changes in Stripe API affecting gateways
- Microservice interface drift incidents
- Kong Gateway mapping failures after backend changes
Timeout misalignmentS: Multi-tier API orchestration
T: Maintain consistent timeout behavior
A: Gateway timeout shorter than backend operation time
R: Gateway returned errors while backend completed successfully
- Inconsistent timeout settings
- Missing timeout strategy
- No timeout propagation
- Backend processing blindness
- Fixed timeout values
Coordinated Timeout Pattern
with balanced timeout configuration
- Client-perceived errors despite successful processing
- AWS Lambda integration timeout issues
- Duplicate operations from retry after timeout
Content type handlingS: Mobile app API platform
T: Support various client content types
A: Incorrect content type handling caused parsing failures
R: API errors for specific mobile client versions
- Strict content type validation
- Missing content negotiation
- Hardcoded media types
- Transformation assumptions
- Charset handling issues
Content Negotiation Pattern
with flexible media type handling
- Mobile client/API gateway compatibility issues
- Character encoding errors in international deployments
- Browser-specific content type handling problems

Configuration & Operational Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Configuration complexityS: Large enterprise API program
T: Manage gateway config across many services
A: Configuration sprawl led to inconsistency and errors
R: Misconfigurations causing outages and security gaps
- Manual configuration processes
- Separate config files/locations
- Environment-specific settings
- Multi-team ownership
- Limited configuration validation
Configuration as Code Pattern
with versioned, validated configurations
- Amazon API Gateway misconfiguration incidents
- Kong declarative config management challenges
- Apigee configuration drift issues
Plugin dependency conflictsS: API gateway with complex processing chain
T: Add new security functionality via plugin
A: Plugin interactions caused unexpected behavior
R: Transaction processing errors from plugin chain issues
- Plugin interdependencies
- Undefined execution order
- Shared context modification
- Missing isolation
- Implicit plugin assumptions
Isolated Plugin Pattern
with explicit dependencies and composition
- Kong plugin interaction bugs
- NGINX module conflicts
- API gateway plugin chain deadlocks
Certificate management failuresS: Financial services API platform
T: Maintain secure TLS connections
A: TLS certificate expired without renewal
R: Complete API unavailability for all clients
- Manual certificate processes
- Missing expiration monitoring
- Certificate sprawl
- Siloed responsibility
- Inadequate renewal automation
Automated Certificate Pattern
with lifecycle management and monitoring
- Major outages from certificate expirations
- Let’s Encrypt integration failures
- TLS certificate rotation incidents
Change management gapsS: Business-critical API infrastructure
T: Implement gateway policy changes safely
A: Untested configuration change deployed to production
R: Widespread API failures affecting multiple customers
- Direct production changes
- Inadequate staged testing
- Missing rollback capability
- Limited change oversight
- Insufficient impact analysis
Multi-phase Deployment Pattern
with progressive exposure and automated verification
- Global API outages from configuration changes
- Fastly edge configuration incidents
- Cloudflare API gateway rule deployment failures

Observability & Monitoring Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Insufficient request tracingS: Complex API transaction flow
T: Troubleshoot intermittent customer errors
A: Limited correlation between gateway and backend services
R: Extended MTTR and customer dissatisfaction
- Missing trace propagation
- Independent logging systems
- Insufficient context capturing
- Distributed transaction blindness
- Gateway-only visibility
Distributed Tracing Pattern
with correlation ID propagation and trace aggregation
- Microservice troubleshooting complexity
- Cross-service debugging challenges
- B2B integration error resolution delays
Misleading health checksS: Multi-service API platform
T: Accurately reflect system health
A: Simplistic health checks showed green despite issues
R: Delayed incident response due to false health status
- Basic connectivity checks only
- Missing functional verification
- Point-in-time health checking
- Aggregate-only health reporting
- Limited health dimensions
Comprehensive Health Model Pattern
with multi-level health assessments
- “Green” dashboards during outages
- Delayed incident detection
- False positive health status incidents
Metric collection gapsS: Business-critical API platform
T: Ensure comprehensive performance visibility
A: Important performance patterns invisible in monitoring
R: Performance degradation detected only after customer impact
- Technical-focused metrics
- Missing business metrics
- Aggregate-only measurements
- Insufficient granularity
- System-centric viewpoint
Multi-dimensional Metrics Pattern
with business and technical KPIs
- Gradual API performance degradation
- Undetected error rate increases
- User experience issues despite “normal” metrics
Alert fatigueS: 24/7 API operations team
T: Maintain reliable notification of actual issues
A: Excessive low-value alerts caused alert fatigue
R: Critical alert missed due to noise, extending outage
- Low threshold settings
- Missing alert correlation
- Alert-on-everything approach
- Static alerting rules
- Insufficient prioritization
Hierarchical Alerting Pattern
with severity-based routing and alert correlation
- On-call fatigue leading to missed incidents
- Alert storms during partial outages
- False positive response burnout

Developer Experience Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Poor API documentationS: Public API platform for developers
T: Enable successful API integration
A: Outdated and incomplete documentation
R: High support volume and integration failures
- Manual documentation processes
- Separate docs from implementation
- Missing examples
- Undefined documentation processes
- Delayed documentation updates
API Documentation as Code Pattern
with generated, validated documentation
- Developer frustration with inconsistent docs
- Stripe API documentation gaps
- Auth0 integration challenges from docs
Inconsistent error responsesS: Partner API integration program
T: Provide actionable error information
A: Inconsistent error formats across endpoints
R: Partner integration delays and increased support costs
- Service-specific error formats
- Missing error standardization
- Passed-through backend errors
- Inconsistent error detail levels
- Varying status code usage
Consistent Error Pattern
with standardized formats and problem details
- Mobile client error handling complexity
- Integration partner complaints
- Error interpretation challenges
Throttling transparencyS: SaaS API with usage-based pricing
T: Communicate rate limits clearly to clients
A: Missing or unclear throttling headers
R: Unexpected client errors and negative user experience
- Silent throttling
- Missing rate information
- Inconsistent limit communication
- Ambiguous error messages
- Fixed rate limits
Transparent Throttling Pattern
with clear limits and proactive notifications
- GitHub API client confusion
- Twitter API rate limit complaints
- AWS API user frustration with unclear limits
Testing challengesS: Enterprise API development program
T: Enable effective client testing
A: Limited sandbox environments and test capabilities
R: Production issues from inadequate pre-release testing
- Production-only authentication
- Missing mock capabilities
- Limited test data
- Environment differences
- Restricted sandbox functionality
Comprehensive Testing Environment Pattern
with realistic sandbox and mock capabilities
- Payment API integration test challenges
- OAuth API testing difficulties
- Third-party API mocking complexity

Compliance & Governance Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Regulatory compliance gapsS: Healthcare API handling PHI data
T: Maintain HIPAA compliance for all API traffic
A: Missing access logging for certain paths
R: Compliance audit findings and potential penalties
- Incomplete compliance coverage
- Manual compliance verification
- Siloed responsibility
- Evolving regulatory requirements
- Feature-first prioritization
Compliance by Design Pattern
with built-in regulatory controls
- GDPR violations from API data handling
- PCI DSS compliance failures
- HIPAA audit findings in API gateways
Data residency violationsS: Multi-national financial services API
T: Comply with regional data sovereignty laws
A: API gateway logged sensitive data across regions
R: Regulatory violations in multiple jurisdictions
- Centralized logging architecture
- Missing data classification
- Location-unaware processing
- Global traffic management
- Insufficient geo-fencing
Data Sovereignty Pattern
with geo-aware request handling
- EU GDPR cross-border transfer violations
- Financial data residency compliance issues
- Healthcare data localization failures
Audit trail gapsS: Banking system API audit
T: Provide complete transaction history
A: Incomplete audit trails for specific transaction types
R: Failed compliance audit and remediation requirements
- Inconsistent audit implementation
- Selective logging practices
- Missing non-repudiation controls
- Audit storage limitations
- Performance-driven audit reduction
Comprehensive Audit Pattern
with guaranteed audit capture
- Financial transaction traceability issues
- SOX compliance gaps in API systems
- Regulatory findings on incomplete audit trails
API governance inconsistencyS: Large enterprise API program
T: Ensure consistent API design across teams
A: Inconsistent patterns and practices across endpoints
R: Poor developer experience and integration challenges
- Team-specific implementations
- Missing governance enforcement
- Optional standards
- Decentralized API ownership
- Organic API growth
API Governance Framework Pattern
with automated standards enforcement
- Enterprise API inconsistency issues
- Versioning strategy inconsistencies
- Field naming convention drift across APIs

Architectural & Design Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
Gateway bypassS: Microservice architecture implementation
T: Enforce consistent API policies
A: Direct service-to-service calls bypassed gateway
R: Security and governance policies circumvented
- Incomplete network controls
- Direct service discovery
- Mixed traffic patterns
- Missing gateway validation
- Convenience-driven shortcuts
API Mesh Pattern
with comprehensive traffic management
- Security policy enforcement gaps
- Inconsistent API behavior
- Shadow IT integration bypass
Excessive gateway responsibilitiesS: API gateway implementation project
T: Implement robust API management
A: Gateway overloaded with business logic
R: Performance bottlenecks and deployment challenges
- “Smart gateway” anti-pattern
- Business logic in gateway
- Feature creep
- Monolithic gateway design
- Extended gateway responsibilities
Responsibility Separation Pattern
with focused gateway functionality
- Gateway deployment rigidity
- Performance bottlenecks
- Gateway as integration hub anti-pattern
State management issuesS: Distributed API platform
T: Scale gateway horizontally for performance
A: Stateful design prevented seamless scaling
R: Session affinity requirements limiting scalability
- Local state storage
- Session-dependent flows
- Stateful plugins/extensions
- Missing state externalization
- Instance-bound processing
Stateless Gateway Pattern
with externalized state management
- Sticky session requirements limiting scale
- Session-based rate limiting failures
- Gateway scaling bottlenecks
Orchestration overloadS: API gateway for microservice integration
T: Provide unified API from multiple services
A: Complex synchronous orchestration created brittle dependencies
R: Cascading failures and performance bottlenecks
- Chatty API design
- Synchronous composition
- Gateway-driven orchestration
- Deep call chains
- Tight backend coupling
Backend for Frontend Pattern
with purpose-built composition services
- Tightly coupled microservice failures
- API gateway timeout cascades
- Orchestration complexity incidents

Edge Cases & Advanced Usage Issues #

IssueSTAR Incident ExampleContributing PatternsCanonical Solution PatternReal-world Incidents
WebSocket handlingS: Real-time trading platform
T: Support persistent WebSocket connections
A: API gateway terminated WebSockets prematurely
R: Interrupted trading sessions and data loss
- HTTP-focused gateway design
- Connection timeout limits
- WebSocket as afterthought
- Load balancer limitations
- Insufficient connection management
Long-lived Connection Pattern
with WebSocket-aware infrastructure
- Trading platform disconnection issues
- Chat application stability problems
- Real-time data streaming interruptions
Large payload handlingS: Media processing API
T: Support file upload through API gateway
A: Large payloads caused gateway timeouts and failures
R: Unreliable media processing and upload failures
- Default size limitations
- Synchronous processing models
- In-memory request handling
- Missing streaming support
- Fixed timeout configurations
Streaming Transfer Pattern
with chunked processing and bypass options
- File upload API failures
- Media processing gateway timeouts
- Memory exhaustion from large payloads
Binary protocol supportS: IoT device management platform
T: Support binary protocols for efficient communication
A: Gateway limited to HTTP/JSON caused protocol impedance
R: Excessive bandwidth usage and battery drain on devices
- Text-protocol focus
- HTTP-only design
- Missing protocol translation
- Inefficient encoding
- Limited content type support
Protocol Adaptation Pattern
with native binary protocol support
- IoT platform efficiency problems
- Mobile app battery drain issues
- Protocol translation overhead challenges
Multi-region data consistencyS: Global API platform with regional deployments
T: Maintain consistent configuration across regions
A: Configuration drift between regions caused inconsistent behavior
R: Regional differences in API behavior confusing clients
- Region-specific deployments
- Manual synchronization
- Independent regional operations
- Missing global view
- Different regional capabilities
Global Consistency Pattern
with version-controlled configuration and synchronization
- Regional API behavior inconsistencies
- Security policy application differences
- Cross-region user experience variations

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