Production Scalability

Comprehensive guide to scalability analysis and optimization in production environments. This guide covers horizontal and vertical scaling strategies, bottleneck identification, capacity planning, and automated scaling systems for maintaining optimal performance under varying loads.

Table of Contents

• Introduction
• Scalability Framework
• Scaling Strategies
• Bottleneck Analysis
• Capacity Planning
• Automated Scaling
• Performance Monitoring
• Cost Optimization
• Best Practices

Introduction

Production scalability ensures systems can handle increasing loads while maintaining performance and availability. This guide provides comprehensive frameworks for implementing effective scalability strategies that balance performance, cost, and operational complexity.

Scalability Framework

package main

import (
    "context"
    "fmt"
    "sync"
    "time"
)

// ScalabilityManager manages production scalability operations
type ScalabilityManager struct {
    config              ScalabilityConfig
    horizontalScaler    *HorizontalScaler
    verticalScaler      *VerticalScaler
    bottleneckAnalyzer  *BottleneckAnalyzer
    capacityPlanner     *CapacityPlanner
    autoScaler          *AutoScaler
    performanceMonitor  *PerformanceMonitor
    costOptimizer       *CostOptimizer
    resourceManager     *ResourceManager
    loadBalancer        *LoadBalancer
    metricsCollector    *MetricsCollector
    alertManager        *AlertManager
    predictionEngine    *PredictionEngine
    optimizationEngine  *OptimizationEngine
    reportGenerator     *ReportGenerator
    auditLogger         *AuditLogger
    mu                  sync.RWMutex
    activeScalingOps    map[string]*ScalingOperation
}

// ScalabilityConfig contains scalability configuration
type ScalabilityConfig struct {
    HorizontalConfig    HorizontalScalingConfig
    VerticalConfig      VerticalScalingConfig
    AutoScalingConfig   AutoScalingConfig
    MonitoringConfig    MonitoringConfig
    CapacityConfig      CapacityPlanningConfig
    CostConfig          CostOptimizationConfig
    PerformanceConfig   PerformanceConfig
    ResourceConfig      ResourceConfig
    AlertingConfig      AlertingConfig
    PredictionConfig    PredictionConfig
    OptimizationConfig  OptimizationConfig
    ComplianceConfig    ComplianceConfig
    SecurityConfig      SecurityConfig
    AuditConfig         AuditConfig
    ReportingConfig     ReportingConfig
}

// HorizontalScalingConfig contains horizontal scaling configuration
type HorizontalScalingConfig struct {
    Enabled         bool
    MinInstances    int
    MaxInstances    int
    TargetUtilization UtilizationTargets
    ScalingPolicies []ScalingPolicy
    LoadBalancing   LoadBalancingConfig
    HealthChecks    HealthCheckConfig
    Deployment      DeploymentConfig
    Network         NetworkConfig
    Storage         StorageConfig
    Security        SecurityConfig
    Monitoring      MonitoringConfig
    Validation      ValidationConfig
    Rollback        RollbackConfig
    Cost            CostConfig
}

// UtilizationTargets defines utilization targets
type UtilizationTargets struct {
    CPU         float64
    Memory      float64
    Network     float64
    Disk        float64
    Custom      map[string]float64
    Composite   CompositeTarget
    Adaptive    bool
    Sensitivity float64
}

// CompositeTarget defines composite targets
type CompositeTarget struct {
    Metrics   []string
    Weights   []float64
    Function  AggregationFunction
    Threshold float64
}

// AggregationFunction defines aggregation functions
type AggregationFunction int

const (
    WeightedAverage AggregationFunction = iota
    Maximum
    Minimum
    Median
    Percentile
    Custom
)

// ScalingPolicy defines scaling policies
type ScalingPolicy struct {
    Name            string
    Type            ScalingType
    Direction       ScalingDirection
    Triggers        []ScalingTrigger
    Actions         []ScalingAction
    Cooldown        time.Duration
    StepSize        int
    StepSizing      StepSizingStrategy
    Validation      PolicyValidation
    Conditions      []PolicyCondition
    Schedule        PolicySchedule
    Override        PolicyOverride
}

// ScalingType defines scaling types
type ScalingType int

const (
    ReactiveScaling ScalingType = iota
    PredictiveScaling
    ScheduledScaling
    HybridScaling
    MLScaling
)

// ScalingDirection defines scaling directions
type ScalingDirection int

const (
    ScaleUp ScalingDirection = iota
    ScaleDown
    Bidirectional
)

// ScalingTrigger defines scaling triggers
type ScalingTrigger struct {
    Metric      string
    Operator    ComparisonOperator
    Threshold   float64
    Duration    time.Duration
    Aggregation AggregationType
    Window      time.Duration
    Conditions  []TriggerCondition
    Weight      float64
    Enabled     bool
}

// TriggerCondition defines trigger conditions
type TriggerCondition struct {
    Expression string
    Required   bool
    Timeout    time.Duration
}

// ScalingAction defines scaling actions
type ScalingAction struct {
    Type        ActionType
    Target      string
    Parameters  map[string]interface{}
    Timeout     time.Duration
    Validation  ActionValidation
    Rollback    ActionRollback
    Conditions  []ActionCondition
    Dependencies []ActionDependency
}

// ActionValidation defines action validation
type ActionValidation struct {
    Enabled   bool
    Tests     []ValidationTest
    Timeout   time.Duration
    Required  bool
    Rollback  bool
}

// ValidationTest defines validation tests
type ValidationTest struct {
    Name      string
    Type      TestType
    Target    string
    Expected  interface{}
    Tolerance float64
    Timeout   time.Duration
}

// TestType defines test types
type TestType int

const (
    HealthTest TestType = iota
    PerformanceTest
    CapacityTest
    ConnectivityTest
    SecurityTest
    ComplianceTest
)

// ActionRollback defines action rollback
type ActionRollback struct {
    Enabled   bool
    Triggers  []RollbackTrigger
    Strategy  RollbackStrategy
    Timeout   time.Duration
    Validation bool
}

// RollbackTrigger defines rollback triggers
type RollbackTrigger struct {
    Condition string
    Threshold float64
    Duration  time.Duration
    Severity  TriggerSeverity
}

// TriggerSeverity defines trigger severity
type TriggerSeverity int

const (
    LowSeverity TriggerSeverity = iota
    MediumSeverity
    HighSeverity
    CriticalSeverity
)

// RollbackStrategy defines rollback strategies
type RollbackStrategy int

const (
    ImmediateRollback RollbackStrategy = iota
    GradualRollback
    ConditionalRollback
    ManualRollback
)

// ActionCondition defines action conditions
type ActionCondition struct {
    Expression string
    Required   bool
    Message    string
}

// ActionDependency defines action dependencies
type ActionDependency struct {
    Action    string
    Type      DependencyType
    Timeout   time.Duration
    Required  bool
}

// DependencyType defines dependency types
type DependencyType int

const (
    Sequential DependencyType = iota
    Parallel
    Conditional
    Optional
)

// StepSizingStrategy defines step sizing strategies
type StepSizingStrategy int

const (
    FixedStep StepSizingStrategy = iota
    ProportionalStep
    AdaptiveStep
    PredictiveStep
)

// PolicyValidation defines policy validation
type PolicyValidation struct {
    Enabled   bool
    Rules     []ValidationRule
    Metrics   []ValidationMetric
    Timeout   time.Duration
    Required  bool
}

// ValidationRule defines validation rules
type ValidationRule struct {
    Name        string
    Expression  string
    Severity    ValidationSeverity
    Action      ValidationAction
    Message     string
}

// ValidationSeverity defines validation severity
type ValidationSeverity int

const (
    InfoValidation ValidationSeverity = iota
    WarningValidation
    ErrorValidation
    CriticalValidation
)

// ValidationAction defines validation actions
type ValidationAction int

const (
    LogValidationAction ValidationAction = iota
    WarnValidationAction
    FailValidationAction
    BlockValidationAction
)

// ValidationMetric defines validation metrics
type ValidationMetric struct {
    Name      string
    Threshold float64
    Operator  ComparisonOperator
    Window    time.Duration
    Critical  bool
}

// PolicyCondition defines policy conditions
type PolicyCondition struct {
    Expression string
    Required   bool
    Timeout    time.Duration
    Message    string
}

// PolicySchedule defines policy schedules
type PolicySchedule struct {
    Enabled   bool
    Windows   []ScheduleWindow
    Timezone  string
    Override  bool
}

// ScheduleWindow defines schedule windows
type ScheduleWindow struct {
    Start     time.Time
    End       time.Time
    Days      []time.Weekday
    Recurring bool
    Active    bool
}

// PolicyOverride defines policy overrides
type PolicyOverride struct {
    Enabled    bool
    Conditions []OverrideCondition
    Approvers  []string
    Timeout    time.Duration
    Audit      bool
}

// OverrideCondition defines override conditions
type OverrideCondition struct {
    Trigger   string
    Rationale string
    Expiry    time.Time
    Approved  bool
}

// LoadBalancingConfig contains load balancing configuration
type LoadBalancingConfig struct {
    Type        LoadBalancerType
    Algorithm   LoadBalancingAlgorithm
    HealthCheck HealthCheckConfig
    Stickiness  StickinessConfig
    SSL         SSLConfig
    Targets     TargetConfig
    Monitoring  MonitoringConfig
    Failover    FailoverConfig
}

// LoadBalancerType defines load balancer types
type LoadBalancerType int

const (
    ApplicationLB LoadBalancerType = iota
    NetworkLB
    ClassicLB
    GatewayLB
    InternalLB
)

// LoadBalancingAlgorithm defines load balancing algorithms
type LoadBalancingAlgorithm int

const (
    RoundRobin LoadBalancingAlgorithm = iota
    LeastConnections
    WeightedRoundRobin
    IPHash
    LeastResponseTime
    ResourceBased
)

// HealthCheckConfig contains health check configuration
type HealthCheckConfig struct {
    Protocol      string
    Path          string
    Port          int
    Interval      time.Duration
    Timeout       time.Duration
    HealthyThreshold   int
    UnhealthyThreshold int
    GracePeriod   time.Duration
    Custom        CustomHealthCheck
}

// CustomHealthCheck defines custom health checks
type CustomHealthCheck struct {
    Enabled   bool
    Script    string
    Command   string
    Expected  string
    Timeout   time.Duration
}

// StickinessConfig contains stickiness configuration
type StickinessConfig struct {
    Enabled  bool
    Type     StickinessType
    Duration time.Duration
    Cookie   CookieConfig
}

// StickinessType defines stickiness types
type StickinessType int

const (
    DurationBased StickinessType = iota
    ApplicationBased
    CookieBased
    IPBased
)

// CookieConfig contains cookie configuration
type CookieConfig struct {
    Name     string
    Domain   string
    Path     string
    Secure   bool
    HttpOnly bool
    SameSite string
}

// SSLConfig contains SSL configuration
type SSLConfig struct {
    Enabled     bool
    Certificate string
    PrivateKey  string
    Protocol    string
    Ciphers     []string
    HSTS        bool
}

// TargetConfig contains target configuration
type TargetConfig struct {
    Registration   TargetRegistration
    Deregistration TargetDeregistration
    Health         TargetHealth
    Routing        TargetRouting
}

// TargetRegistration defines target registration
type TargetRegistration struct {
    Automatic bool
    Discovery ServiceDiscovery
    Validation TargetValidation
    Timeout   time.Duration
}

// ServiceDiscovery defines service discovery
type ServiceDiscovery struct {
    Type     DiscoveryType
    Endpoint string
    Interval time.Duration
    Tags     map[string]string
}

// DiscoveryType defines discovery types
type DiscoveryType int

const (
    DNSDiscovery DiscoveryType = iota
    ConsulDiscovery
    EtcdDiscovery
    KubernetesDiscovery
    EurekaDiscovery
)

// TargetValidation defines target validation
type TargetValidation struct {
    Enabled bool
    Tests   []ValidationTest
    Timeout time.Duration
    Retry   RetryConfig
}

// RetryConfig contains retry configuration
type RetryConfig struct {
    MaxAttempts int
    Delay       time.Duration
    Backoff     BackoffStrategy
    Conditions  []RetryCondition
}

// BackoffStrategy defines backoff strategies
type BackoffStrategy int

const (
    FixedBackoff BackoffStrategy = iota
    LinearBackoff
    ExponentialBackoff
    RandomBackoff
)

// RetryCondition defines retry conditions
type RetryCondition struct {
    Type      ConditionType
    Pattern   string
    Retryable bool
}

// ConditionType defines condition types
type ConditionType int

const (
    ErrorCondition ConditionType = iota
    TimeoutCondition
    StatusCondition
    CustomCondition
)

// TargetDeregistration defines target deregistration
type TargetDeregistration struct {
    Graceful   bool
    Timeout    time.Duration
    DrainTime  time.Duration
    Validation DeregistrationValidation
}

// DeregistrationValidation defines deregistration validation
type DeregistrationValidation struct {
    Enabled     bool
    Connections ConnectionValidation
    Requests    RequestValidation
    Health      HealthValidation
}

// ConnectionValidation defines connection validation
type ConnectionValidation struct {
    MaxActive  int
    DrainTime  time.Duration
    ForceClose bool
}

// RequestValidation defines request validation
type RequestValidation struct {
    InFlight    int
    Completion  time.Duration
    ForceCancel bool
}

// HealthValidation defines health validation
type HealthValidation struct {
    Checks   int
    Interval time.Duration
    Timeout  time.Duration
}

// TargetHealth defines target health
type TargetHealth struct {
    Monitoring HealthMonitoring
    Recovery   HealthRecovery
    Quarantine HealthQuarantine
}

// HealthMonitoring defines health monitoring
type HealthMonitoring struct {
    Continuous bool
    Interval   time.Duration
    Metrics    []string
    Alerts     []string
}

// HealthRecovery defines health recovery
type HealthRecovery struct {
    Automatic   bool
    Criteria    []RecoveryCriteria
    Validation  RecoveryValidation
    GracePeriod time.Duration
}

// RecoveryCriteria defines recovery criteria
type RecoveryCriteria struct {
    Metric    string
    Threshold float64
    Duration  time.Duration
    Required  bool
}

// RecoveryValidation defines recovery validation
type RecoveryValidation struct {
    Tests    []ValidationTest
    Timeout  time.Duration
    Required bool
}

// HealthQuarantine defines health quarantine
type HealthQuarantine struct {
    Enabled  bool
    Duration time.Duration
    Criteria []QuarantineCriteria
    Actions  []QuarantineAction
}

// QuarantineCriteria defines quarantine criteria
type QuarantineCriteria struct {
    Condition string
    Threshold float64
    Duration  time.Duration
    Severity  TriggerSeverity
}

// QuarantineAction defines quarantine actions
type QuarantineAction struct {
    Type       ActionType
    Parameters map[string]interface{}
    Timeout    time.Duration
    Validation bool
}

// TargetRouting defines target routing
type TargetRouting struct {
    Strategy    RoutingStrategy
    Weights     map[string]float64
    Rules       []RoutingRule
    Fallback    RoutingFallback
}

// RoutingStrategy defines routing strategies
type RoutingStrategy int

const (
    WeightedRouting RoutingStrategy = iota
    RoundRobinRouting
    PerformanceRouting
    GeographicRouting
    CustomRouting
)

// RoutingRule defines routing rules
type RoutingRule struct {
    Condition string
    Target    string
    Weight    float64
    Priority  int
}

// RoutingFallback defines routing fallback
type RoutingFallback struct {
    Enabled bool
    Target  string
    Timeout time.Duration
    Health  bool
}

// FailoverConfig contains failover configuration
type FailoverConfig struct {
    Enabled    bool
    Strategy   FailoverStrategy
    Detection  FailoverDetection
    Recovery   FailoverRecovery
    Validation FailoverValidation
}

// FailoverStrategy defines failover strategies
type FailoverStrategy int

const (
    ActivePassive FailoverStrategy = iota
    ActiveActive
    MultiRegion
    MultiCloud
    Hybrid
)

// FailoverDetection defines failover detection
type FailoverDetection struct {
    Triggers  []FailoverTrigger
    Timeout   time.Duration
    Validation DetectionValidation
}

// FailoverTrigger defines failover triggers
type FailoverTrigger struct {
    Type      TriggerType
    Condition string
    Threshold float64
    Duration  time.Duration
}

// DetectionValidation defines detection validation
type DetectionValidation struct {
    Enabled bool
    Tests   []ValidationTest
    Timeout time.Duration
    Quorum  QuorumConfig
}

// QuorumConfig contains quorum configuration
type QuorumConfig struct {
    Enabled   bool
    MinNodes  int
    Consensus float64
    Timeout   time.Duration
}

// FailoverRecovery defines failover recovery
type FailoverRecovery struct {
    Automatic  bool
    Strategy   RecoveryStrategy
    Validation RecoveryValidation
    Timeout    time.Duration
}

// RecoveryStrategy defines recovery strategies
type RecoveryStrategy int

const (
    GradualRecovery RecoveryStrategy = iota
    ImmediateRecovery
    TestRecovery
    ManualRecovery
)

// FailoverValidation defines failover validation
type FailoverValidation struct {
    PreFailover  []ValidationTest
    PostFailover []ValidationTest
    Continuous   []ValidationTest
    Timeout      time.Duration
}

// VerticalScalingConfig contains vertical scaling configuration
type VerticalScalingConfig struct {
    Enabled       bool
    Resources     ResourceScaling
    Policies      []VerticalPolicy
    Validation    VerticalValidation
    Rollback      VerticalRollback
    Monitoring    MonitoringConfig
    Cost          CostConfig
    Security      SecurityConfig
    Compliance    ComplianceConfig
}

// ResourceScaling defines resource scaling
type ResourceScaling struct {
    CPU     CPUScaling
    Memory  MemoryScaling
    Storage StorageScaling
    Network NetworkScaling
    GPU     GPUScaling
    Custom  map[string]CustomResourceScaling
}

// CPUScaling defines CPU scaling
type CPUScaling struct {
    Enabled     bool
    MinCores    float64
    MaxCores    float64
    StepSize    float64
    TargetUtil  float64
    Constraints CPUConstraints
}

// CPUConstraints defines CPU constraints
type CPUConstraints struct {
    Architecture []string
    Features     []string
    Isolation    bool
    Affinity     AffinityRule
}

// AffinityRule defines affinity rules
type AffinityRule struct {
    Type     AffinityType
    Target   string
    Weight   int
    Required bool
}

// AffinityType defines affinity types
type AffinityType int

const (
    NodeAffinity AffinityType = iota
    PodAffinity
    AntiAffinity
    ZoneAffinity
)

// MemoryScaling defines memory scaling
type MemoryScaling struct {
    Enabled     bool
    MinMemory   int64
    MaxMemory   int64
    StepSize    int64
    TargetUtil  float64
    Constraints MemoryConstraints
}

// MemoryConstraints defines memory constraints
type MemoryConstraints struct {
    Type       MemoryType
    Speed      int
    ECC        bool
    Bandwidth  int64
    Isolation  bool
}

// MemoryType defines memory types
type MemoryType int

const (
    DDR4Memory MemoryType = iota
    DDR5Memory
    HBMMemory
    NVRAMMemory
)

// StorageScaling defines storage scaling
type StorageScaling struct {
    Enabled     bool
    MinStorage  int64
    MaxStorage  int64
    StepSize    int64
    TargetUtil  float64
    Constraints StorageConstraints
}

// StorageConstraints defines storage constraints
type StorageConstraints struct {
    Type        StorageType
    Performance PerformanceTier
    Redundancy  RedundancyLevel
    Encryption  bool
    Backup      bool
}

// StorageType defines storage types
type StorageType int

const (
    SSDStorage StorageType = iota
    NVMeStorage
    HDDStorage
    NetworkStorage
    ObjectStorage
)

// PerformanceTier defines performance tiers
type PerformanceTier int

const (
    StandardTier PerformanceTier = iota
    PerformanceTier
    PremiumTier
    UltraTier
)

// RedundancyLevel defines redundancy levels
type RedundancyLevel int

const (
    NoRedundancy RedundancyLevel = iota
    MirroredRedundancy
    StripedRedundancy
    DistributedRedundancy
)

// NetworkScaling defines network scaling
type NetworkScaling struct {
    Enabled     bool
    MinBandwidth int64
    MaxBandwidth int64
    StepSize    int64
    TargetUtil  float64
    Constraints NetworkConstraints
}

// NetworkConstraints defines network constraints
type NetworkConstraints struct {
    Type      NetworkType
    Latency   time.Duration
    Jitter    time.Duration
    PacketLoss float64
    QoS       QoSConfig
}

// NetworkType defines network types
type NetworkType int

const (
    EthernetNetwork NetworkType = iota
    InfiniBandNetwork
    FibreChannelNetwork
    WirelessNetwork
)

// QoSConfig contains QoS configuration
type QoSConfig struct {
    Enabled    bool
    Classes    []QoSClass
    Policies   []QoSPolicy
    Monitoring bool
}

// QoSClass defines QoS classes
type QoSClass struct {
    Name        string
    Priority    int
    Bandwidth   int64
    Latency     time.Duration
    PacketLoss  float64
    Jitter      time.Duration
}

// QoSPolicy defines QoS policies
type QoSPolicy struct {
    Name      string
    Rules     []QoSRule
    Actions   []QoSAction
    Enabled   bool
}

// QoSRule defines QoS rules
type QoSRule struct {
    Condition string
    Class     string
    Priority  int
}

// QoSAction defines QoS actions
type QoSAction struct {
    Type       QoSActionType
    Parameters map[string]interface{}
    Timeout    time.Duration
}

// QoSActionType defines QoS action types
type QoSActionType int

const (
    RateLimitAction QoSActionType = iota
    PriorityAction
    DropAction
    MarkAction
)

// GPUScaling defines GPU scaling
type GPUScaling struct {
    Enabled     bool
    MinGPUs     int
    MaxGPUs     int
    StepSize    int
    TargetUtil  float64
    Constraints GPUConstraints
}

// GPUConstraints defines GPU constraints
type GPUConstraints struct {
    Type        GPUType
    Memory      int64
    Compute     ComputeCapability
    Interconnect InterconnectType
    Sharing     SharingMode
}

// GPUType defines GPU types
type GPUType int

const (
    NVIDIA_GPU GPUType = iota
    AMD_GPU
    Intel_GPU
    ARM_GPU
    Custom_GPU
)

// ComputeCapability defines compute capabilities
type ComputeCapability struct {
    Major   int
    Minor   int
    Features []string
}

// InterconnectType defines interconnect types
type InterconnectType int

const (
    PCIeInterconnect InterconnectType = iota
    NVLinkInterconnect
    InfiniBandInterconnect
    EthernetInterconnect
)

// SharingMode defines sharing modes
type SharingMode int

const (
    ExclusiveSharing SharingMode = iota
    TimeSlicingSharing
    MPSSharing
    VirtualGPUSharing
)

// CustomResourceScaling defines custom resource scaling
type CustomResourceScaling struct {
    Enabled     bool
    MinValue    float64
    MaxValue    float64
    StepSize    float64
    TargetUtil  float64
    Unit        string
    Constraints map[string]interface{}
}

// VerticalPolicy defines vertical scaling policies
type VerticalPolicy struct {
    Name        string
    Resources   []string
    Triggers    []ScalingTrigger
    Actions     []ScalingAction
    Schedule    PolicySchedule
    Validation  PolicyValidation
    Rollback    PolicyRollback
}

// PolicyRollback defines policy rollback
type PolicyRollback struct {
    Enabled   bool
    Triggers  []RollbackTrigger
    Strategy  RollbackStrategy
    Timeout   time.Duration
    Validation RollbackValidation
}

// RollbackValidation defines rollback validation
type RollbackValidation struct {
    Enabled bool
    Tests   []ValidationTest
    Timeout time.Duration
    Automatic bool
}

// VerticalValidation defines vertical scaling validation
type VerticalValidation struct {
    Enabled    bool
    PreScaling []ValidationTest
    PostScaling []ValidationTest
    Continuous []ValidationTest
    Timeout    time.Duration
}

// VerticalRollback defines vertical scaling rollback
type VerticalRollback struct {
    Enabled   bool
    Automatic bool
    Triggers  []RollbackTrigger
    Strategy  RollbackStrategy
    Timeout   time.Duration
    Validation RollbackValidation
}

// ScalingOperation represents an active scaling operation
type ScalingOperation struct {
    ID           string
    Type         OperationType
    Direction    ScalingDirection
    Target       string
    StartTime    time.Time
    EndTime      time.Time
    Status       OperationStatus
    Progress     float64
    Metrics      OperationMetrics
    Validation   OperationValidation
    Rollback     OperationRollback
    Events       []OperationEvent
}

// OperationType defines operation types
type OperationType int

const (
    HorizontalOperation OperationType = iota
    VerticalOperation
    HybridOperation
    PredictiveOperation
)

// OperationStatus defines operation status
type OperationStatus int

const (
    PendingOperation OperationStatus = iota
    RunningOperation
    ValidatingOperation
    CompletedOperation
    FailedOperation
    RolledBackOperation
    CancelledOperation
)

// OperationMetrics contains operation metrics
type OperationMetrics struct {
    Duration       time.Duration
    ResourcesAdded int
    ResourcesRemoved int
    CostImpact     float64
    PerformanceImpact PerformanceImpact
    Efficiency     float64
}

// PerformanceImpact defines performance impact
type PerformanceImpact struct {
    Latency    time.Duration
    Throughput float64
    ErrorRate  float64
    Availability float64
}

// OperationValidation contains operation validation
type OperationValidation struct {
    Tests    []ValidationTest
    Results  []ValidationResult
    Passed   bool
    Score    float64
    Issues   []ValidationIssue
}

// ValidationResult contains validation results
type ValidationResult struct {
    Test     string
    Status   ValidationStatus
    Value    interface{}
    Expected interface{}
    Message  string
}

// ValidationStatus defines validation status
type ValidationStatus int

const (
    PassedValidation ValidationStatus = iota
    WarningValidation
    FailedValidation
    SkippedValidation
)

// ValidationIssue defines validation issues
type ValidationIssue struct {
    Type        IssueType
    Severity    IssueSeverity
    Description string
    Resolution  string
    Impact      string
}

// IssueType defines issue types
type IssueType int

const (
    PerformanceIssue IssueType = iota
    SecurityIssue
    ComplianceIssue
    CostIssue
    CapacityIssue
)

// IssueSeverity defines issue severity
type IssueSeverity int

const (
    InfoSeverity IssueSeverity = iota
    WarningSeverity
    ErrorSeverity
    CriticalSeverity
)

// OperationRollback contains operation rollback
type OperationRollback struct {
    Enabled   bool
    Reason    string
    Strategy  RollbackStrategy
    Executed  bool
    Success   bool
    Duration  time.Duration
}

// OperationEvent defines operation events
type OperationEvent struct {
    Timestamp   time.Time
    Type        EventType
    Description string
    Metadata    map[string]interface{}
}

// EventType defines event types
type EventType int

const (
    StartEvent EventType = iota
    ProgressEvent
    ValidationEvent
    ErrorEvent
    WarningEvent
    CompletionEvent
    RollbackEvent
)

// Component type definitions
type HorizontalScaler struct{}
type VerticalScaler struct{}
type BottleneckAnalyzer struct{}
type CapacityPlanner struct{}
type AutoScaler struct{}
type PerformanceMonitor struct{}
type CostOptimizer struct{}
type ResourceManager struct{}
type LoadBalancer struct{}
type MetricsCollector struct{}
type AlertManager struct{}
type PredictionEngine struct{}
type OptimizationEngine struct{}
type ReportGenerator struct{}
type AuditLogger struct{}
type AutoScalingConfig struct{}
type MonitoringConfig struct{}
type CapacityPlanningConfig struct{}
type CostOptimizationConfig struct{}
type PerformanceConfig struct{}
type ResourceConfig struct{}
type AlertingConfig struct{}
type PredictionConfig struct{}
type OptimizationConfig struct{}
type ComplianceConfig struct{}
type SecurityConfig struct{}
type AuditConfig struct{}
type ReportingConfig struct{}
type DeploymentConfig struct{}
type NetworkConfig struct{}
type StorageConfig struct{}
type ValidationConfig struct{}
type RollbackConfig struct{}
type CostConfig struct{}
type ComparisonOperator struct{}
type AggregationType struct{}
type ActionType struct{}

// NewScalabilityManager creates a new scalability manager
func NewScalabilityManager(config ScalabilityConfig) *ScalabilityManager {
    return &ScalabilityManager{
        config:             config,
        horizontalScaler:   &HorizontalScaler{},
        verticalScaler:     &VerticalScaler{},
        bottleneckAnalyzer: &BottleneckAnalyzer{},
        capacityPlanner:    &CapacityPlanner{},
        autoScaler:         &AutoScaler{},
        performanceMonitor: &PerformanceMonitor{},
        costOptimizer:      &CostOptimizer{},
        resourceManager:    &ResourceManager{},
        loadBalancer:       &LoadBalancer{},
        metricsCollector:   &MetricsCollector{},
        alertManager:       &AlertManager{},
        predictionEngine:   &PredictionEngine{},
        optimizationEngine: &OptimizationEngine{},
        reportGenerator:    &ReportGenerator{},
        auditLogger:        &AuditLogger{},
        activeScalingOps:   make(map[string]*ScalingOperation),
    }
}

// Scale performs scaling operations based on current conditions
func (s *ScalabilityManager) Scale(ctx context.Context, request ScalingRequest) (*ScalingOperation, error) {
    s.mu.Lock()
    defer s.mu.Unlock()

    fmt.Printf("Processing scaling request: %s\n", request.Type)

    // Create scaling operation
    operation := &ScalingOperation{
        ID:        fmt.Sprintf("scale-%d", time.Now().Unix()),
        Type:      request.Type,
        Direction: request.Direction,
        Target:    request.Target,
        StartTime: time.Now(),
        Status:    RunningOperation,
        Progress:  0.0,
        Metrics:   OperationMetrics{},
        Events:    []OperationEvent{},
    }

    s.activeScalingOps[operation.ID] = operation

    // Execute scaling operation
    if err := s.executeScaling(ctx, operation, request); err != nil {
        operation.Status = FailedOperation
        return nil, fmt.Errorf("scaling execution failed: %w", err)
    }

    // Validate scaling operation
    if err := s.validateScaling(ctx, operation); err != nil {
        // Trigger rollback on validation failure
        if rollbackErr := s.rollbackScaling(ctx, operation, err.Error()); rollbackErr != nil {
            fmt.Printf("Rollback failed: %v\n", rollbackErr)
        }
        return nil, fmt.Errorf("scaling validation failed: %w", err)
    }

    operation.Status = CompletedOperation
    operation.EndTime = time.Now()
    operation.Progress = 100.0

    fmt.Printf("Scaling operation completed: %s\n", operation.ID)

    return operation, nil
}

// ScalingRequest represents a scaling request
type ScalingRequest struct {
    Type      OperationType
    Direction ScalingDirection
    Target    string
    Magnitude int
    Reason    string
    Priority  int
    Metadata  map[string]interface{}
}

func (s *ScalabilityManager) executeScaling(ctx context.Context, operation *ScalingOperation, request ScalingRequest) error {
    // Scaling execution logic
    fmt.Printf("Executing scaling operation: %s\n", operation.Type)

    // Add operation event
    event := OperationEvent{
        Timestamp:   time.Now(),
        Type:        StartEvent,
        Description: "Scaling operation started",
        Metadata:    map[string]interface{}{"target": request.Target},
    }
    operation.Events = append(operation.Events, event)

    // Simulate scaling operation
    time.Sleep(time.Second * 2)
    operation.Progress = 50.0

    // Progress event
    progressEvent := OperationEvent{
        Timestamp:   time.Now(),
        Type:        ProgressEvent,
        Description: "Scaling operation 50% complete",
        Metadata:    map[string]interface{}{"progress": 50.0},
    }
    operation.Events = append(operation.Events, progressEvent)

    // Complete operation
    time.Sleep(time.Second * 2)
    operation.Progress = 100.0

    return nil
}

func (s *ScalabilityManager) validateScaling(ctx context.Context, operation *ScalingOperation) error {
    // Scaling validation logic
    fmt.Printf("Validating scaling operation: %s\n", operation.ID)

    operation.Status = ValidatingOperation

    // Validation event
    event := OperationEvent{
        Timestamp:   time.Now(),
        Type:        ValidationEvent,
        Description: "Scaling validation started",
        Metadata:    map[string]interface{}{},
    }
    operation.Events = append(operation.Events, event)

    // Simulate validation
    time.Sleep(time.Second)

    operation.Validation = OperationValidation{
        Passed: true,
        Score:  95.0,
        Issues: []ValidationIssue{},
    }

    return nil
}

func (s *ScalabilityManager) rollbackScaling(ctx context.Context, operation *ScalingOperation, reason string) error {
    // Scaling rollback logic
    fmt.Printf("Rolling back scaling operation: %s, reason: %s\n", operation.ID, reason)

    operation.Status = RolledBackOperation
    operation.Rollback = OperationRollback{
        Enabled:  true,
        Reason:   reason,
        Strategy: ImmediateRollback,
        Executed: true,
        Success:  true,
        Duration: time.Second * 30,
    }

    // Rollback event
    event := OperationEvent{
        Timestamp:   time.Now(),
        Type:        RollbackEvent,
        Description: "Scaling operation rolled back",
        Metadata:    map[string]interface{}{"reason": reason},
    }
    operation.Events = append(operation.Events, event)

    return nil
}

// Example usage
func ExampleScalabilityManagement() {
    config := ScalabilityConfig{
        HorizontalConfig: HorizontalScalingConfig{
            Enabled:      true,
            MinInstances: 2,
            MaxInstances: 20,
            TargetUtilization: UtilizationTargets{
                CPU:    70.0,
                Memory: 80.0,
            },
        },
        VerticalConfig: VerticalScalingConfig{
            Enabled: true,
            Resources: ResourceScaling{
                CPU: CPUScaling{
                    Enabled:    true,
                    MinCores:   1.0,
                    MaxCores:   16.0,
                    StepSize:   0.5,
                    TargetUtil: 70.0,
                },
                Memory: MemoryScaling{
                    Enabled:    true,
                    MinMemory:  1024 * 1024 * 1024, // 1GB
                    MaxMemory:  64 * 1024 * 1024 * 1024, // 64GB
                    StepSize:   1024 * 1024 * 1024, // 1GB
                    TargetUtil: 80.0,
                },
            },
        },
    }

    manager := NewScalabilityManager(config)

    // Horizontal scaling request
    request := ScalingRequest{
        Type:      HorizontalOperation,
        Direction: ScaleUp,
        Target:    "web-service",
        Magnitude: 3,
        Reason:    "High CPU utilization detected",
        Priority:  1,
        Metadata:  map[string]interface{}{"trigger": "cpu_threshold"},
    }

    ctx := context.Background()
    operation, err := manager.Scale(ctx, request)
    if err != nil {
        fmt.Printf("Scaling operation failed: %v\n", err)
        return
    }

    fmt.Printf("Scaling Operation - ID: %s, Status: %d, Progress: %.1f%%\n", 
        operation.ID, operation.Status, operation.Progress)
}

Scaling Strategies

Comprehensive scaling strategies for different scenarios and requirements.

Horizontal Scaling

Scale-out strategies with load balancing and service orchestration.

Vertical Scaling

Scale-up strategies with resource optimization and constraint management.

Hybrid Scaling

Combined horizontal and vertical scaling for optimal resource utilization.

Predictive Scaling

Machine learning-based scaling predictions and proactive resource management.

Bottleneck Analysis

Advanced bottleneck identification and resolution strategies.

Performance Profiling

Comprehensive performance profiling and bottleneck identification.

Resource Analysis

Detailed resource utilization analysis and optimization recommendations.

Dependency Mapping

Service dependency analysis and critical path identification.

Capacity Modeling

Mathematical modeling for capacity planning and optimization.

Best Practices

1. Comprehensive Monitoring: Monitor all key performance indicators
2. Predictive Scaling: Use predictive algorithms for proactive scaling
3. Cost Optimization: Balance performance needs with cost constraints
4. Automated Validation: Implement automated scaling validation
5. Gradual Changes: Use gradual scaling to minimize impact
6. Rollback Capability: Ensure quick rollback for failed operations
7. Resource Efficiency: Optimize resource utilization across all dimensions
8. Continuous Learning: Use feedback to improve scaling algorithms

Summary

Production scalability management provides comprehensive scaling capabilities:

1. Multi-dimensional Scaling: Support for both horizontal and vertical scaling
2. Intelligent Automation: AI-driven scaling decisions and predictions
3. Cost Optimization: Balance between performance and cost efficiency
4. Advanced Analytics: Comprehensive bottleneck analysis and optimization
5. Safety Mechanisms: Automated validation and rollback capabilities
6. Real-time Adaptation: Dynamic response to changing load patterns

These capabilities enable organizations to maintain optimal performance while efficiently managing resources and costs in production environments.