Streaming Optimization

Comprehensive guide to optimizing streaming data processing in Go applications. This guide covers stream processing patterns, backpressure management, memory optimization, and performance tuning for high-throughput streaming systems.

Table of Contents

• Introduction
• Stream Processing Framework
• Backpressure Management
• Memory Optimization
• Throughput Optimization
• Latency Optimization
• Monitoring and Metrics
• Best Practices

Introduction

Streaming optimization is crucial for building high-performance data processing systems in Go. This guide provides comprehensive strategies for optimizing stream processing pipelines, managing backpressure, and achieving optimal throughput and latency characteristics.

Stream Processing Framework

package main

import (
    "context"
    "fmt"
    "io"
    "runtime"
    "sync"
    "sync/atomic"
    "time"
    "unsafe"
)

// StreamProcessor manages high-performance stream processing
type StreamProcessor struct {
    pipelines   map[string]*StreamPipeline
    scheduler   *StreamScheduler
    monitor     *StreamMonitor
    optimizer   *StreamOptimizer
    config      StreamProcessorConfig
    metrics     *StreamMetrics
    mu          sync.RWMutex
}

// StreamProcessorConfig contains processor configuration
type StreamProcessorConfig struct {
    MaxPipelines        int
    DefaultBufferSize   int
    MaxBufferSize       int
    WorkerPoolSize      int
    EnableBackpressure  bool
    EnableOptimization  bool
    EnableMonitoring    bool
    OptimizationPeriod  time.Duration
    MonitoringInterval  time.Duration
    GCTriggerThreshold  float64
}

// StreamPipeline represents a data processing pipeline
type StreamPipeline struct {
    ID              string
    Name            string
    Stages          []*ProcessingStage
    Source          StreamSource
    Sink            StreamSink
    Config          PipelineConfig
    State           PipelineState
    Stats           *PipelineStatistics
    BackpressureCtrl *BackpressureController
    BufferManager   *StreamBufferManager
    ErrorHandler    ErrorHandler
    mu              sync.RWMutex
}

// PipelineConfig contains pipeline configuration
type PipelineConfig struct {
    BufferSize          int
    MaxLatency          time.Duration
    MaxThroughput       float64
    Parallelism         int
    EnableBackpressure  bool
    BackpressureStrategy BackpressureStrategy
    MemoryLimit         int64
    ErrorHandling       ErrorHandlingStrategy
    Checkpointing       CheckpointConfig
}

// PipelineState represents pipeline states
type PipelineState int

const (
    PipelineCreated PipelineState = iota
    PipelineStarting
    PipelineRunning
    PipelinePaused
    PipelineStopping
    PipelineStopped
    PipelineError
)

// PipelineStatistics tracks pipeline performance
type PipelineStatistics struct {
    MessagesProcessed   int64
    MessagesDropped     int64
    BytesProcessed      int64
    ProcessingLatency   time.Duration
    Throughput          float64
    ErrorRate           float64
    BackpressureEvents  int64
    MemoryUsage         int64
    CPUUsage            float64
    LastProcessedTime   time.Time
}

// ProcessingStage represents a processing stage in the pipeline
type ProcessingStage struct {
    ID          string
    Name        string
    Processor   StreamProcessor
    Config      StageConfig
    Stats       *StageStatistics
    Input       <-chan StreamMessage
    Output      chan<- StreamMessage
    Workers     []*StageWorker
    State       StageState
    mu          sync.RWMutex
}

// StageConfig contains stage configuration
type StageConfig struct {
    WorkerCount         int
    BufferSize          int
    MaxBatchSize        int
    BatchTimeout        time.Duration
    EnableBatching      bool
    EnableParallelism   bool
    MemoryLimit         int64
    ProcessingTimeout   time.Duration
}

// StageStatistics tracks stage performance
type StageStatistics struct {
    MessagesIn          int64
    MessagesOut         int64
    MessagesDropped     int64
    ProcessingTime      time.Duration
    WaitTime            time.Duration
    ErrorCount          int64
    BackpressureCount   int64
    WorkerUtilization   float64
}

// StageState represents stage states
type StageState int

const (
    StageIdle StageState = iota
    StageProcessing
    StageBlocked
    StageError
)

// StageWorker processes messages in a stage
type StageWorker struct {
    ID          int
    Stage       *ProcessingStage
    Input       <-chan StreamMessage
    Output      chan<- StreamMessage
    Stats       *WorkerStatistics
    State       WorkerState
    ctx         context.Context
    cancel      context.CancelFunc
    mu          sync.RWMutex
}

// WorkerStatistics tracks worker performance
type WorkerStatistics struct {
    MessagesProcessed   int64
    ProcessingTime      time.Duration
    IdleTime            time.Duration
    ErrorCount          int64
    LastActivity        time.Time
    Utilization         float64
}

// WorkerState represents worker states
type WorkerState int

const (
    WorkerIdle WorkerState = iota
    WorkerProcessing
    WorkerBlocked
    WorkerError
    WorkerShutdown
)

// StreamMessage represents a message in the stream
type StreamMessage struct {
    ID          string
    Payload     interface{}
    Headers     map[string]string
    Timestamp   time.Time
    Size        int64
    Priority    MessagePriority
    TTL         time.Duration
    Checksum    uint64
    Metadata    map[string]interface{}
}

// MessagePriority defines message priority levels
type MessagePriority int

const (
    LowPriority MessagePriority = iota
    NormalPriority
    HighPriority
    CriticalPriority
)

// StreamSource provides data to the pipeline
type StreamSource interface {
    Read(ctx context.Context) (<-chan StreamMessage, error)
    Close() error
    GetMetrics() map[string]interface{}
}

// StreamSink consumes data from the pipeline
type StreamSink interface {
    Write(ctx context.Context, messages <-chan StreamMessage) error
    Close() error
    GetMetrics() map[string]interface{}
}

// StreamScheduler manages pipeline execution scheduling
type StreamScheduler struct {
    pipelines   []*StreamPipeline
    scheduler   Scheduler
    resources   *ResourceManager
    config      SchedulerConfig
    metrics     *SchedulerMetrics
    mu          sync.RWMutex
}

// SchedulerConfig contains scheduler configuration
type SchedulerConfig struct {
    SchedulingPolicy    SchedulingPolicy
    MaxConcurrentPipes  int
    ResourceLimits      ResourceLimits
    PriorityLevels      int
    PreemptionEnabled   bool
}

// SchedulingPolicy defines scheduling policies
type SchedulingPolicy int

const (
    RoundRobinScheduling SchedulingPolicy = iota
    PriorityScheduling
    FairShareScheduling
    DeadlineScheduling
)

// ResourceLimits defines resource constraints
type ResourceLimits struct {
    MaxMemory       int64
    MaxCPU          float64
    MaxGoroutines   int
    MaxFileHandles  int
}

// SchedulerMetrics tracks scheduler performance
type SchedulerMetrics struct {
    PipelinesScheduled  int64
    SchedulingLatency   time.Duration
    ResourceUtilization ResourceUtilization
    QueueDepth          int32
    Preemptions         int64
}

// ResourceUtilization tracks resource usage
type ResourceUtilization struct {
    Memory      float64
    CPU         float64
    Goroutines  int
    FileHandles int
}

// BackpressureController manages backpressure in the pipeline
type BackpressureController struct {
    strategy    BackpressureStrategy
    thresholds  BackpressureThresholds
    metrics     *BackpressureMetrics
    actions     []BackpressureAction
    state       BackpressureState
    mu          sync.RWMutex
}

// BackpressureStrategy defines backpressure handling strategies
type BackpressureStrategy int

const (
    DropStrategy BackpressureStrategy = iota
    BlockStrategy
    ThrottleStrategy
    SpillStrategy
    LoadShedStrategy
)

// BackpressureThresholds defines when to apply backpressure
type BackpressureThresholds struct {
    MemoryThreshold     float64
    LatencyThreshold    time.Duration
    ThroughputThreshold float64
    QueueSizeThreshold  int
    ErrorRateThreshold  float64
}

// BackpressureMetrics tracks backpressure events
type BackpressureMetrics struct {
    EventsTriggered     int64
    MessagesDropped     int64
    ThrottlingDuration  time.Duration
    SpilledMessages     int64
    LoadShedEvents      int64
    RecoveryTime        time.Duration
}

// BackpressureState represents backpressure states
type BackpressureState int

const (
    NormalPressure BackpressureState = iota
    LowPressure
    MediumPressure
    HighPressure
    CriticalPressure
)

// BackpressureAction represents an action to take under backpressure
type BackpressureAction interface {
    Execute(ctx context.Context, pipeline *StreamPipeline) error
    GetType() BackpressureActionType
    GetSeverity() ActionSeverity
}

// BackpressureActionType defines action types
type BackpressureActionType int

const (
    DropAction BackpressureActionType = iota
    ThrottleAction
    SpillAction
    LoadShedAction
    ScaleAction
)

// ActionSeverity defines action severity
type ActionSeverity int

const (
    LowSeverity ActionSeverity = iota
    MediumSeverity
    HighSeverity
    CriticalSeverity
)

// StreamBufferManager manages buffers for streaming
type StreamBufferManager struct {
    buffers     map[string]*StreamBuffer
    allocator   BufferAllocator
    monitor     *BufferMonitor
    config      BufferManagerConfig
    metrics     *BufferManagerMetrics
    mu          sync.RWMutex
}

// StreamBuffer represents a streaming buffer
type StreamBuffer struct {
    ID          string
    Data        []byte
    Size        int
    Capacity    int
    ReadPos     int
    WritePos    int
    Watermark   int
    State       BufferState
    Stats       *BufferStatistics
    mu          sync.RWMutex
}

// BufferState represents buffer states
type BufferState int

const (
    BufferEmpty BufferState = iota
    BufferPartial
    BufferFull
    BufferOverflow
)

// BufferStatistics tracks buffer performance
type BufferStatistics struct {
    BytesRead       int64
    BytesWritten    int64
    Overflows       int64
    Underflows      int64
    Utilization     float64
    ThroughputMBps  float64
}

// StreamMonitor monitors streaming performance
type StreamMonitor struct {
    events      chan StreamEvent
    collectors  []StreamCollector
    analyzer    *StreamAnalyzer
    alerting    *StreamAlerting
    dashboard   *StreamDashboard
    running     bool
    mu          sync.RWMutex
}

// StreamEvent represents a streaming event
type StreamEvent struct {
    Type        StreamEventType
    PipelineID  string
    StageID     string
    Timestamp   time.Time
    Data        interface{}
    Severity    EventSeverity
    Message     string
    Metadata    map[string]interface{}
}

// StreamEventType defines event types
type StreamEventType int

const (
    MessageProcessed StreamEventType = iota
    MessageDropped
    BackpressureTriggered
    ErrorOccurred
    LatencyThresholdExceeded
    ThroughputChanged
    MemoryUsageChanged
)

// EventSeverity defines event severity
type EventSeverity int

const (
    InfoSeverity EventSeverity = iota
    WarningSeverity
    ErrorSeverity
    CriticalSeverity
)

// StreamCollector collects streaming metrics
type StreamCollector interface {
    CollectEvent(event StreamEvent)
    GetMetrics() map[string]interface{}
    Reset()
}

// StreamAnalyzer analyzes streaming patterns
type StreamAnalyzer struct {
    patterns    map[string]*StreamPattern
    trends      *StreamTrends
    predictor   *StreamPredictor
    config      AnalyzerConfig
}

// StreamPattern represents a streaming pattern
type StreamPattern struct {
    Name            string
    Type            PatternType
    Characteristics map[string]float64
    Frequency       float64
    Confidence      float64
    Optimization    PatternOptimization
}

// PatternType defines pattern types
type PatternType int

const (
    BurstPattern PatternType = iota
    SteadyPattern
    SeasonalPattern
    SpikePattern
    DropPattern
)

// PatternOptimization contains pattern-specific optimizations
type PatternOptimization struct {
    RecommendedBufferSize   int
    RecommendedParallelism  int
    BackpressureStrategy    BackpressureStrategy
    PerformanceGains        map[string]float64
}

// StreamTrends tracks streaming trends
type StreamTrends struct {
    ThroughputTrend     TrendDirection
    LatencyTrend        TrendDirection
    ErrorRateTrend      TrendDirection
    MemoryUsageTrend    TrendDirection
    PredictedChanges    map[string]float64
}

// TrendDirection defines trend directions
type TrendDirection int

const (
    TrendIncreasing TrendDirection = iota
    TrendDecreasing
    TrendStable
    TrendVolatile
)

// StreamPredictor predicts streaming behavior
type StreamPredictor struct {
    models      map[string]*PredictionModel
    forecasts   map[string]*Forecast
    config      PredictorConfig
}

// PredictionModel represents a prediction model
type PredictionModel struct {
    Type        ModelType
    Parameters  map[string]float64
    Accuracy    float64
    LastTrained time.Time
}

// ModelType defines prediction model types
type ModelType int

const (
    LinearModel ModelType = iota
    TimeSeriesModel
    MachineLearningModel
    StatisticalModel
)

// Forecast represents a prediction forecast
type Forecast struct {
    Metric      string
    Horizon     time.Duration
    Values      []float64
    Confidence  []float64
    UpdatedAt   time.Time
}

// StreamOptimizer optimizes streaming performance
type StreamOptimizer struct {
    strategies  []OptimizationStrategy
    evaluator   *PerformanceEvaluator
    simulator   *StreamSimulator
    config      OptimizerConfig
}

// OptimizationStrategy defines optimization strategies
type OptimizationStrategy interface {
    Analyze(pipeline *StreamPipeline) (*OptimizationResult, error)
    Apply(pipeline *StreamPipeline, result *OptimizationResult) error
    Validate(pipeline *StreamPipeline) error
}

// OptimizationResult contains optimization results
type OptimizationResult struct {
    Strategy            string
    ExpectedImprovement PerformanceImprovement
    Changes             []ConfigurationChange
    Risks               []OptimizationRisk
    Validation          ValidationResult
}

// PerformanceImprovement represents expected improvements
type PerformanceImprovement struct {
    ThroughputIncrease  float64
    LatencyReduction    float64
    MemoryReduction     float64
    CPUReduction        float64
    OverallScore        float64
}

// ConfigurationChange represents a configuration change
type ConfigurationChange struct {
    Component   string
    Parameter   string
    OldValue    interface{}
    NewValue    interface{}
    Impact      string
    RiskLevel   RiskLevel
}

// RiskLevel defines optimization risk levels
type RiskLevel int

const (
    LowRisk RiskLevel = iota
    MediumRisk
    HighRisk
    CriticalRisk
)

// OptimizationRisk represents optimization risks
type OptimizationRisk struct {
    Type        RiskType
    Severity    RiskSeverity
    Description string
    Mitigation  string
    Probability float64
}

// RiskType defines risk types
type RiskType int

const (
    PerformanceRisk RiskType = iota
    StabilityRisk
    CompatibilityRisk
    SecurityRisk
)

// RiskSeverity defines risk severity
type RiskSeverity int

const (
    LowRiskSeverity RiskSeverity = iota
    MediumRiskSeverity
    HighRiskSeverity
    CriticalRiskSeverity
)

// ValidationResult contains validation results
type ValidationResult struct {
    Valid       bool
    Confidence  float64
    Issues      []ValidationIssue
    Warnings    []string
    Metrics     map[string]float64
}

// ValidationIssue represents a validation issue
type ValidationIssue struct {
    Type        IssueType
    Severity    IssueSeverity
    Description string
    Component   string
    Suggestion  string
}

// IssueType defines validation issue types
type IssueType int

const (
    ConfigurationIssue IssueType = iota
    PerformanceIssue
    CompatibilityIssue
    SecurityIssue
)

// IssueSeverity defines issue severity
type IssueSeverity int

const (
    MinorIssue IssueSeverity = iota
    MajorIssue
    CriticalIssue
)

// StreamMetrics tracks overall streaming metrics
type StreamMetrics struct {
    TotalPipelines      int32
    ActivePipelines     int32
    TotalMessages       int64
    MessagesPerSecond   float64
    AverageLatency      time.Duration
    TotalThroughput     float64
    MemoryUsage         int64
    CPUUsage            float64
    ErrorRate           float64
    BackpressureEvents  int64
}

// ErrorHandler handles streaming errors
type ErrorHandler interface {
    HandleError(ctx context.Context, err error, message *StreamMessage) ErrorAction
    GetErrorStats() map[string]interface{}
}

// ErrorAction defines error handling actions
type ErrorAction int

const (
    RetryAction ErrorAction = iota
    SkipAction
    DeadLetterAction
    FailPipelineAction
)

// CheckpointConfig contains checkpointing configuration
type CheckpointConfig struct {
    Enabled         bool
    Interval        time.Duration
    Storage         CheckpointStorage
    CompressionType CompressionType
    Retention       time.Duration
}

// CheckpointStorage defines checkpoint storage types
type CheckpointStorage int

const (
    MemoryStorage CheckpointStorage = iota
    DiskStorage
    RemoteStorage
)

// CompressionType defines compression types
type CompressionType int

const (
    NoCompression CompressionType = iota
    GzipCompression
    LZ4Compression
    SnappyCompression
)

// NewStreamProcessor creates a new stream processor
func NewStreamProcessor(config StreamProcessorConfig) *StreamProcessor {
    return &StreamProcessor{
        pipelines: make(map[string]*StreamPipeline),
        scheduler: NewStreamScheduler(),
        monitor:   NewStreamMonitor(),
        optimizer: NewStreamOptimizer(),
        config:    config,
        metrics:   &StreamMetrics{},
    }
}

// CreatePipeline creates a new streaming pipeline
func (sp *StreamProcessor) CreatePipeline(id, name string, config PipelineConfig) (*StreamPipeline, error) {
    sp.mu.Lock()
    defer sp.mu.Unlock()

    if _, exists := sp.pipelines[id]; exists {
        return nil, fmt.Errorf("pipeline %s already exists", id)
    }

    pipeline := &StreamPipeline{
        ID:              id,
        Name:            name,
        Stages:          make([]*ProcessingStage, 0),
        Config:          config,
        State:           PipelineCreated,
        Stats:           &PipelineStatistics{},
        BackpressureCtrl: NewBackpressureController(config.BackpressureStrategy),
        BufferManager:   NewStreamBufferManager(),
        ErrorHandler:    NewDefaultErrorHandler(),
    }

    sp.pipelines[id] = pipeline
    atomic.AddInt32(&sp.metrics.TotalPipelines, 1)

    return pipeline, nil
}

// AddStage adds a processing stage to the pipeline
func (p *StreamPipeline) AddStage(id, name string, processor StreamProcessor, config StageConfig) (*ProcessingStage, error) {
    p.mu.Lock()
    defer p.mu.Unlock()

    stage := &ProcessingStage{
        ID:        id,
        Name:      name,
        Processor: processor,
        Config:    config,
        Stats:     &StageStatistics{},
        Workers:   make([]*StageWorker, config.WorkerCount),
        State:     StageIdle,
    }

    // Create input and output channels
    stage.Input = make(<-chan StreamMessage, config.BufferSize)
    stage.Output = make(chan<- StreamMessage, config.BufferSize)

    // Create workers
    for i := 0; i < config.WorkerCount; i++ {
        worker := &StageWorker{
            ID:    i,
            Stage: stage,
            Stats: &WorkerStatistics{},
            State: WorkerIdle,
        }
        worker.ctx, worker.cancel = context.WithCancel(context.Background())
        stage.Workers[i] = worker
    }

    p.Stages = append(p.Stages, stage)

    return stage, nil
}

// Start starts the streaming pipeline
func (p *StreamPipeline) Start(ctx context.Context) error {
    p.mu.Lock()
    defer p.mu.Unlock()

    if p.State != PipelineCreated && p.State != PipelineStopped {
        return fmt.Errorf("pipeline cannot be started in state %v", p.State)
    }

    p.State = PipelineStarting

    // Start all stages
    for _, stage := range p.Stages {
        if err := stage.Start(ctx); err != nil {
            p.State = PipelineError
            return fmt.Errorf("failed to start stage %s: %w", stage.ID, err)
        }
    }

    // Start source and sink
    if p.Source != nil {
        go p.runSource(ctx)
    }

    if p.Sink != nil {
        go p.runSink(ctx)
    }

    p.State = PipelineRunning
    return nil
}

// Start starts a processing stage
func (s *ProcessingStage) Start(ctx context.Context) error {
    s.mu.Lock()
    defer s.mu.Unlock()

    if s.State != StageIdle {
        return fmt.Errorf("stage cannot be started in state %v", s.State)
    }

    // Start all workers
    for _, worker := range s.Workers {
        go worker.run()
    }

    s.State = StageProcessing
    return nil
}

// run executes the worker loop
func (w *StageWorker) run() {
    defer func() {
        w.mu.Lock()
        w.State = WorkerShutdown
        w.mu.Unlock()
    }()

    for {
        select {
        case <-w.ctx.Done():
            return

        case message, ok := <-w.Input:
            if !ok {
                return
            }

            w.processMessage(message)
        }
    }
}

// processMessage processes a single message
func (w *StageWorker) processMessage(message StreamMessage) {
    w.mu.Lock()
    w.State = WorkerProcessing
    start := time.Now()
    w.mu.Unlock()

    defer func() {
        duration := time.Since(start)
        w.mu.Lock()
        w.Stats.MessagesProcessed++
        w.Stats.ProcessingTime += duration
        w.Stats.LastActivity = time.Now()
        w.State = WorkerIdle
        w.mu.Unlock()

        // Update stage statistics
        atomic.AddInt64(&w.Stage.Stats.MessagesIn, 1)
        atomic.AddInt64(&w.Stage.Stats.MessagesOut, 1)
    }()

    // Process the message (placeholder implementation)
    processedMessage := w.transformMessage(message)

    // Send to output
    select {
    case w.Output <- processedMessage:
        // Message sent successfully
    case <-w.ctx.Done():
        return
    default:
        // Output channel full, handle backpressure
        w.handleBackpressure(processedMessage)
    }
}

// transformMessage transforms a message (placeholder)
func (w *StageWorker) transformMessage(message StreamMessage) StreamMessage {
    // Placeholder transformation logic
    message.Headers["processed_by"] = fmt.Sprintf("worker_%d", w.ID)
    message.Headers["processed_at"] = time.Now().Format(time.RFC3339)
    return message
}

// handleBackpressure handles backpressure situations
func (w *StageWorker) handleBackpressure(message StreamMessage) {
    atomic.AddInt64(&w.Stage.Stats.BackpressureCount, 1)

    // For now, just drop the message
    atomic.AddInt64(&w.Stage.Stats.MessagesDropped, 1)
}

// runSource runs the pipeline source
func (p *StreamPipeline) runSource(ctx context.Context) {
    if p.Source == nil {
        return
    }

    messages, err := p.Source.Read(ctx)
    if err != nil {
        // Handle source error
        return
    }

    for {
        select {
        case <-ctx.Done():
            return

        case message, ok := <-messages:
            if !ok {
                return
            }

            // Send to first stage
            if len(p.Stages) > 0 {
                select {
                case p.Stages[0].Input <- message:
                    atomic.AddInt64(&p.Stats.MessagesProcessed, 1)
                case <-ctx.Done():
                    return
                }
            }
        }
    }
}

// runSink runs the pipeline sink
func (p *StreamPipeline) runSink(ctx context.Context) {
    if p.Sink == nil || len(p.Stages) == 0 {
        return
    }

    lastStage := p.Stages[len(p.Stages)-1]
    err := p.Sink.Write(ctx, lastStage.Output)
    if err != nil {
        // Handle sink error
    }
}

// NewBackpressureController creates a new backpressure controller
func NewBackpressureController(strategy BackpressureStrategy) *BackpressureController {
    return &BackpressureController{
        strategy: strategy,
        thresholds: BackpressureThresholds{
            MemoryThreshold:     0.8,
            LatencyThreshold:    100 * time.Millisecond,
            ThroughputThreshold: 1000.0,
            QueueSizeThreshold:  10000,
            ErrorRateThreshold:  0.05,
        },
        metrics: &BackpressureMetrics{},
        actions: make([]BackpressureAction, 0),
        state:   NormalPressure,
    }
}

// NewStreamBufferManager creates a new stream buffer manager
func NewStreamBufferManager() *StreamBufferManager {
    return &StreamBufferManager{
        buffers:   make(map[string]*StreamBuffer),
        allocator: NewBufferAllocator(),
        monitor:   NewBufferMonitor(),
        config:    BufferManagerConfig{},
        metrics:   &BufferManagerMetrics{},
    }
}

// NewStreamScheduler creates a new stream scheduler
func NewStreamScheduler() *StreamScheduler {
    return &StreamScheduler{
        pipelines: make([]*StreamPipeline, 0),
        scheduler: NewScheduler(),
        resources: NewResourceManager(),
        config: SchedulerConfig{
            SchedulingPolicy:   RoundRobinScheduling,
            MaxConcurrentPipes: 100,
            PriorityLevels:     5,
            PreemptionEnabled:  true,
        },
        metrics: &SchedulerMetrics{},
    }
}

// NewStreamMonitor creates a new stream monitor
func NewStreamMonitor() *StreamMonitor {
    return &StreamMonitor{
        events:     make(chan StreamEvent, 10000),
        collectors: make([]StreamCollector, 0),
        analyzer:   NewStreamAnalyzer(),
        alerting:   NewStreamAlerting(),
        dashboard:  NewStreamDashboard(),
    }
}

// Start starts the stream monitor
func (sm *StreamMonitor) Start() error {
    sm.mu.Lock()
    defer sm.mu.Unlock()

    if sm.running {
        return fmt.Errorf("monitor already running")
    }

    sm.running = true
    go sm.monitorLoop()

    return nil
}

// monitorLoop processes stream events
func (sm *StreamMonitor) monitorLoop() {
    ticker := time.NewTicker(time.Second)
    defer ticker.Stop()

    for sm.running {
        select {
        case event := <-sm.events:
            sm.processEvent(event)

        case <-ticker.C:
            sm.performPeriodicTasks()
        }
    }
}

// processEvent processes a single stream event
func (sm *StreamMonitor) processEvent(event StreamEvent) {
    // Notify collectors
    for _, collector := range sm.collectors {
        collector.CollectEvent(event)
    }

    // Analyze event
    if sm.analyzer != nil {
        sm.analyzer.ProcessEvent(event)
    }

    // Check for alerts
    sm.checkAlerts(event)
}

// checkAlerts checks for alert conditions
func (sm *StreamMonitor) checkAlerts(event StreamEvent) {
    // Implementation would check various alert conditions
}

// performPeriodicTasks performs periodic monitoring tasks
func (sm *StreamMonitor) performPeriodicTasks() {
    // Update metrics, analyze trends, etc.
}

// NewStreamOptimizer creates a new stream optimizer
func NewStreamOptimizer() *StreamOptimizer {
    return &StreamOptimizer{
        strategies: []OptimizationStrategy{
            &ThroughputOptimizationStrategy{},
            &LatencyOptimizationStrategy{},
            &MemoryOptimizationStrategy{},
            &BackpressureOptimizationStrategy{},
        },
        evaluator: NewPerformanceEvaluator(),
        simulator: NewStreamSimulator(),
    }
}

// Optimization strategies
type ThroughputOptimizationStrategy struct{}
type LatencyOptimizationStrategy struct{}
type MemoryOptimizationStrategy struct{}
type BackpressureOptimizationStrategy struct{}

// Stream components
type Scheduler interface{}
type ResourceManager struct{}
type BufferAllocator interface{}
type BufferMonitor struct{}
type BufferManagerConfig struct{}
type BufferManagerMetrics struct{}
type StreamAnalyzer struct{}
type StreamAlerting struct{}
type StreamDashboard struct{}
type PerformanceEvaluator struct{}
type StreamSimulator struct{}
type DefaultErrorHandler struct{}

// Constructor functions for components
func NewScheduler() Scheduler { return nil }
func NewResourceManager() *ResourceManager { return &ResourceManager{} }
func NewBufferAllocator() BufferAllocator { return nil }
func NewBufferMonitor() *BufferMonitor { return &BufferMonitor{} }
func NewStreamAnalyzer() *StreamAnalyzer { return &StreamAnalyzer{} }
func NewStreamAlerting() *StreamAlerting { return &StreamAlerting{} }
func NewStreamDashboard() *StreamDashboard { return &StreamDashboard{} }
func NewPerformanceEvaluator() *PerformanceEvaluator { return &PerformanceEvaluator{} }
func NewStreamSimulator() *StreamSimulator { return &StreamSimulator{} }
func NewDefaultErrorHandler() *DefaultErrorHandler { return &DefaultErrorHandler{} }

// ProcessEvent methods for analyzer
func (sa *StreamAnalyzer) ProcessEvent(event StreamEvent) {}

// GetMetrics returns stream processor metrics
func (sp *StreamProcessor) GetMetrics() *StreamMetrics {
    sp.mu.RLock()
    defer sp.mu.RUnlock()

    metrics := *sp.metrics

    // Aggregate metrics from all pipelines
    totalMessages := int64(0)
    totalLatency := time.Duration(0)
    activeCount := int32(0)

    for _, pipeline := range sp.pipelines {
        if pipeline.State == PipelineRunning {
            activeCount++
        }
        totalMessages += pipeline.Stats.MessagesProcessed
        totalLatency += pipeline.Stats.ProcessingLatency
    }

    metrics.ActivePipelines = activeCount
    metrics.TotalMessages = totalMessages

    if len(sp.pipelines) > 0 {
        metrics.AverageLatency = totalLatency / time.Duration(len(sp.pipelines))
    }

    return &metrics
}

// Example streaming patterns

// BurstBuffer implements a burst-tolerant buffer
type BurstBuffer struct {
    normalCapacity  int
    burstCapacity   int
    data            []StreamMessage
    watermark       int
    state           BufferState
    mu              sync.RWMutex
}

// NewBurstBuffer creates a new burst buffer
func NewBurstBuffer(normalCap, burstCap int) *BurstBuffer {
    return &BurstBuffer{
        normalCapacity: normalCap,
        burstCapacity:  burstCap,
        data:           make([]StreamMessage, 0, burstCap),
        watermark:      normalCap,
        state:          BufferEmpty,
    }
}

// Write writes a message to the burst buffer
func (bb *BurstBuffer) Write(message StreamMessage) bool {
    bb.mu.Lock()
    defer bb.mu.Unlock()

    if len(bb.data) >= bb.burstCapacity {
        return false // Buffer full
    }

    bb.data = append(bb.data, message)

    // Update state based on current fill level
    fillLevel := len(bb.data)
    switch {
    case fillLevel == 0:
        bb.state = BufferEmpty
    case fillLevel < bb.normalCapacity:
        bb.state = BufferPartial
    case fillLevel < bb.burstCapacity:
        bb.state = BufferFull
    default:
        bb.state = BufferOverflow
    }

    return true
}

// Read reads a message from the burst buffer
func (bb *BurstBuffer) Read() (StreamMessage, bool) {
    bb.mu.Lock()
    defer bb.mu.Unlock()

    if len(bb.data) == 0 {
        return StreamMessage{}, false
    }

    message := bb.data[0]
    bb.data = bb.data[1:]

    return message, true
}

// AdaptiveBuffer implements an adaptive buffer that adjusts size based on load
type AdaptiveBuffer struct {
    minSize     int
    maxSize     int
    currentSize int
    data        []StreamMessage
    metrics     *AdaptiveBufferMetrics
    mu          sync.RWMutex
}

// AdaptiveBufferMetrics tracks adaptive buffer performance
type AdaptiveBufferMetrics struct {
    SizeChanges     int64
    OverflowEvents  int64
    UnderflowEvents int64
    Efficiency      float64
    LastResized     time.Time
}

// NewAdaptiveBuffer creates a new adaptive buffer
func NewAdaptiveBuffer(minSize, maxSize int) *AdaptiveBuffer {
    return &AdaptiveBuffer{
        minSize:     minSize,
        maxSize:     maxSize,
        currentSize: minSize,
        data:        make([]StreamMessage, 0, minSize),
        metrics:     &AdaptiveBufferMetrics{},
    }
}

// adjustSize adjusts buffer size based on usage patterns
func (ab *AdaptiveBuffer) adjustSize() {
    ab.mu.Lock()
    defer ab.mu.Unlock()

    utilizationRate := float64(len(ab.data)) / float64(ab.currentSize)

    var newSize int
    if utilizationRate > 0.8 && ab.currentSize < ab.maxSize {
        // Increase size
        newSize = min(ab.currentSize*2, ab.maxSize)
    } else if utilizationRate < 0.2 && ab.currentSize > ab.minSize {
        // Decrease size
        newSize = max(ab.currentSize/2, ab.minSize)
    } else {
        return // No change needed
    }

    // Resize the buffer
    newData := make([]StreamMessage, len(ab.data), newSize)
    copy(newData, ab.data)
    ab.data = newData
    ab.currentSize = newSize
    ab.metrics.SizeChanges++
    ab.metrics.LastResized = time.Now()
}

// ZeroCopyStream implements zero-copy streaming
type ZeroCopyStream struct {
    pages       []*MemoryPage
    readOffset  int64
    writeOffset int64
    pageSize    int
    mu          sync.RWMutex
}

// MemoryPage represents a memory page for zero-copy operations
type MemoryPage struct {
    Data     []byte
    Size     int
    RefCount int32
    Mapped   bool
}

// NewZeroCopyStream creates a new zero-copy stream
func NewZeroCopyStream(pageSize int) *ZeroCopyStream {
    return &ZeroCopyStream{
        pages:    make([]*MemoryPage, 0),
        pageSize: pageSize,
    }
}

// WriteZeroCopy writes data using zero-copy techniques
func (zcs *ZeroCopyStream) WriteZeroCopy(data []byte) error {
    zcs.mu.Lock()
    defer zcs.mu.Unlock()

    // Create memory page for the data
    page := &MemoryPage{
        Data:     data,
        Size:     len(data),
        RefCount: 1,
        Mapped:   true,
    }

    zcs.pages = append(zcs.pages, page)
    zcs.writeOffset += int64(len(data))

    return nil
}

// ReadZeroCopy reads data using zero-copy techniques
func (zcs *ZeroCopyStream) ReadZeroCopy() ([]byte, error) {
    zcs.mu.Lock()
    defer zcs.mu.Unlock()

    if len(zcs.pages) == 0 {
        return nil, io.EOF
    }

    page := zcs.pages[0]
    zcs.pages = zcs.pages[1:]

    // Return reference to the data without copying
    atomic.AddInt32(&page.RefCount, 1)

    return page.Data, nil
}

// Utility functions
func min(a, b int) int {
    if a < b {
        return a
    }
    return b
}

func max(a, b int) int {
    if a > b {
        return a
    }
    return b
}

// Example usage
func ExampleStreamingOptimization() {
    // Create stream processor
    config := StreamProcessorConfig{
        MaxPipelines:        10,
        DefaultBufferSize:   1000,
        MaxBufferSize:       10000,
        WorkerPoolSize:      runtime.NumCPU(),
        EnableBackpressure:  true,
        EnableOptimization:  true,
        EnableMonitoring:    true,
        OptimizationPeriod:  time.Minute,
        MonitoringInterval:  time.Second,
        GCTriggerThreshold:  0.8,
    }

    processor := NewStreamProcessor(config)

    // Create pipeline
    pipelineConfig := PipelineConfig{
        BufferSize:          1000,
        MaxLatency:          100 * time.Millisecond,
        MaxThroughput:       10000.0,
        Parallelism:         4,
        EnableBackpressure:  true,
        BackpressureStrategy: ThrottleStrategy,
        MemoryLimit:         1024 * 1024 * 1024, // 1GB
        ErrorHandling:       RetryAction,
    }

    pipeline, err := processor.CreatePipeline("example-pipeline", "Example Pipeline", pipelineConfig)
    if err != nil {
        fmt.Printf("Failed to create pipeline: %v\n", err)
        return
    }

    // Add processing stages
    stageConfig := StageConfig{
        WorkerCount:       4,
        BufferSize:        100,
        MaxBatchSize:      10,
        BatchTimeout:      10 * time.Millisecond,
        EnableBatching:    true,
        EnableParallelism: true,
        MemoryLimit:       100 * 1024 * 1024, // 100MB
        ProcessingTimeout: 5 * time.Second,
    }

    _, err = pipeline.AddStage("stage1", "Data Validation", nil, stageConfig)
    if err != nil {
        fmt.Printf("Failed to add stage: %v\n", err)
        return
    }

    _, err = pipeline.AddStage("stage2", "Data Transformation", nil, stageConfig)
    if err != nil {
        fmt.Printf("Failed to add stage: %v\n", err)
        return
    }

    // Start pipeline
    ctx := context.Background()
    err = pipeline.Start(ctx)
    if err != nil {
        fmt.Printf("Failed to start pipeline: %v\n", err)
        return
    }

    // Get metrics after processing
    time.Sleep(5 * time.Second)
    metrics := processor.GetMetrics()

    fmt.Printf("Total pipelines: %d\n", metrics.TotalPipelines)
    fmt.Printf("Active pipelines: %d\n", metrics.ActivePipelines)
    fmt.Printf("Messages processed: %d\n", metrics.TotalMessages)
    fmt.Printf("Average latency: %v\n", metrics.AverageLatency)
    fmt.Printf("Total throughput: %.2f msg/s\n", metrics.TotalThroughput)
    fmt.Printf("Memory usage: %d bytes\n", metrics.MemoryUsage)
    fmt.Printf("Error rate: %.2f%%\n", metrics.ErrorRate*100)

    // Example burst buffer usage
    burstBuffer := NewBurstBuffer(100, 1000)

    message := StreamMessage{
        ID:        "msg-1",
        Payload:   "example data",
        Timestamp: time.Now(),
        Size:      12,
        Priority:  NormalPriority,
    }

    success := burstBuffer.Write(message)
    fmt.Printf("Message written to burst buffer: %t\n", success)

    readMessage, ok := burstBuffer.Read()
    fmt.Printf("Message read from burst buffer: %t, ID: %s\n", ok, readMessage.ID)

    // Example adaptive buffer usage
    adaptiveBuffer := NewAdaptiveBuffer(10, 1000)
    adaptiveBuffer.adjustSize()

    fmt.Printf("Adaptive buffer current size: %d\n", adaptiveBuffer.currentSize)
    fmt.Printf("Adaptive buffer metrics - Size changes: %d\n", adaptiveBuffer.metrics.SizeChanges)

    // Example zero-copy streaming
    zcStream := NewZeroCopyStream(4096)

    data := []byte("example streaming data")
    err = zcStream.WriteZeroCopy(data)
    if err != nil {
        fmt.Printf("Failed to write zero-copy data: %v\n", err)
    }

    readData, err := zcStream.ReadZeroCopy()
    if err != nil {
        fmt.Printf("Failed to read zero-copy data: %v\n", err)
    } else {
        fmt.Printf("Zero-copy data read: %s\n", string(readData))
    }
}

Backpressure Management

Advanced techniques for managing backpressure in streaming systems to prevent system overload and maintain performance.

Adaptive Backpressure

Implementing adaptive backpressure mechanisms that adjust based on system load and performance metrics.

Multi-Level Backpressure

Using multi-level backpressure strategies for different types of load and priority levels.

Predictive Backpressure

Implementing predictive backpressure based on trend analysis and load forecasting.

Memory Optimization

Specialized memory optimization techniques for streaming applications.

Zero-Copy Streaming

Implementing zero-copy techniques to minimize memory operations in streaming pipelines.

Memory Pool Management

Using specialized memory pools for streaming workloads with predictable allocation patterns.

Garbage Collection Optimization

Optimizing garbage collection behavior for streaming applications with continuous data flow.

Best Practices

1. Buffer Sizing: Size buffers appropriately for your workload patterns
2. Backpressure: Implement robust backpressure mechanisms
3. Monitoring: Monitor streaming performance continuously
4. Resource Management: Manage CPU, memory, and I/O resources efficiently
5. Error Handling: Implement comprehensive error handling strategies
6. Checkpointing: Use checkpointing for fault tolerance
7. Testing: Test streaming systems under various load conditions
8. Optimization: Continuously optimize based on performance metrics

Summary

Streaming optimization is essential for high-performance data processing applications:

1. Architecture: Design efficient streaming architectures
2. Backpressure: Implement effective backpressure management
3. Memory: Optimize memory usage for streaming workloads
4. Monitoring: Monitor performance and adjust configurations
5. Optimization: Apply continuous optimization techniques

These techniques enable developers to build robust, high-performance streaming systems that can handle large volumes of data efficiently while maintaining low latency and high throughput.