sklears_compose/
stress_testing.rs

1//! Stress Testing Framework for Complex Pipelines
2//!
3//! Comprehensive stress testing framework for evaluating pipeline performance under
4//! extreme conditions including high load, resource constraints, and edge cases.
5
6use chrono::{DateTime, Utc};
7use scirs2_core::ndarray::{Array1, Array2};
8use scirs2_core::random::{thread_rng, Rng};
9use serde::{Deserialize, Serialize};
10use sklears_core::{error::Result as SklResult, traits::Estimator};
11use std::collections::HashMap;
12use std::sync::{Arc, Mutex};
13use std::thread;
14use std::time::{Duration, Instant};
15
16/// Stress testing framework for complex machine learning pipelines
17pub struct StressTester {
18    /// Test configuration
19    pub config: StressTestConfig,
20    /// Resource monitoring
21    pub resource_monitor: ResourceMonitor,
22    /// Test scenarios
23    pub scenarios: Vec<StressTestScenario>,
24    /// Results storage
25    pub results: Vec<StressTestResult>,
26}
27
28/// Configuration for stress testing
29#[derive(Debug, Clone, Serialize, Deserialize)]
30pub struct StressTestConfig {
31    /// Maximum test duration
32    pub max_duration: Duration,
33    /// Memory limit in MB
34    pub memory_limit_mb: u64,
35    /// CPU usage threshold (0.0 to 1.0)
36    pub cpu_threshold: f64,
37    /// Number of concurrent threads
38    pub max_threads: usize,
39    /// Data scale factors to test
40    pub data_scale_factors: Vec<f64>,
41    /// Pipeline complexity levels
42    pub complexity_levels: Vec<usize>,
43    /// Error tolerance threshold
44    pub error_tolerance: f64,
45    /// Performance degradation threshold
46    pub performance_threshold: f64,
47    /// Enable memory leak detection
48    pub detect_memory_leaks: bool,
49    /// Enable deadlock detection
50    pub detect_deadlocks: bool,
51}
52
53impl Default for StressTestConfig {
54    fn default() -> Self {
55        Self {
56            max_duration: Duration::from_secs(300), // 5 minutes
57            memory_limit_mb: 2048,                  // 2GB
58            cpu_threshold: 0.95,
59            max_threads: 16,
60            data_scale_factors: vec![1.0, 5.0, 10.0, 50.0, 100.0],
61            complexity_levels: vec![1, 5, 10, 25, 50],
62            error_tolerance: 0.01,
63            performance_threshold: 2.0, // 2x slowdown threshold
64            detect_memory_leaks: true,
65            detect_deadlocks: true,
66        }
67    }
68}
69
70/// Different stress test scenarios
71#[derive(Debug, Clone, Serialize, Deserialize)]
72pub enum StressTestScenario {
73    /// High volume data processing
74    HighVolumeData {
75        scale_factor: f64,
76        batch_size: usize,
77    },
78    /// Concurrent pipeline execution
79    ConcurrentExecution {
80        num_threads: usize,
81        num_pipelines: usize,
82    },
83    /// Memory pressure testing
84    MemoryPressure {
85        target_memory_mb: u64,
86        allocation_pattern: MemoryPattern,
87    },
88    /// CPU intensive operations
89    CpuIntensive {
90        complexity_level: usize,
91        computation_type: ComputationType,
92    },
93    /// Long running stability test
94    LongRunning {
95        duration: Duration,
96        operation_interval: Duration,
97    },
98    /// Resource starvation
99    ResourceStarvation {
100        memory_limit_mb: u64,
101        cpu_limit_percent: f64,
102    },
103    /// Edge case handling
104    EdgeCaseHandling { edge_cases: Vec<EdgeCase> },
105}
106
107/// Memory allocation patterns for testing
108#[derive(Debug, Clone, Serialize, Deserialize)]
109pub enum MemoryPattern {
110    /// Gradual increase
111    Gradual,
112    /// Sudden spikes
113    Spiky,
114    /// Fragmented allocations
115    Fragmented,
116    /// Sustained high usage
117    Sustained,
118}
119
120/// Computation types for CPU stress testing
121#[derive(Debug, Clone, Serialize, Deserialize)]
122pub enum ComputationType {
123    /// Matrix operations
124    MatrixOps,
125    /// Iterative algorithms
126    Iterative,
127    /// Recursive operations
128    Recursive,
129    /// Parallel computations
130    Parallel,
131}
132
133/// Edge cases for stress testing
134#[derive(Debug, Clone, Serialize, Deserialize)]
135pub enum EdgeCase {
136    /// Empty datasets
137    EmptyData,
138    /// Single sample datasets
139    SingleSample,
140    /// Extremely large feature dimensions
141    HighDimensional { dimensions: usize },
142    /// Datasets with all identical values
143    IdenticalValues,
144    /// Datasets with extreme outliers
145    ExtremeOutliers { outlier_magnitude: f64 },
146    /// Datasets with missing values
147    MissingValues { missing_ratio: f64 },
148    /// Highly correlated features
149    HighlyCorrelated { correlation: f64 },
150    /// Numerical precision edge cases
151    NumericalEdges,
152}
153
154/// Resource monitoring during stress tests
155#[derive(Debug, Clone)]
156pub struct ResourceMonitor {
157    /// Memory usage samples
158    pub memory_usage: Arc<Mutex<Vec<(DateTime<Utc>, u64)>>>,
159    /// CPU usage samples
160    pub cpu_usage: Arc<Mutex<Vec<(DateTime<Utc>, f64)>>>,
161    /// Thread count samples
162    pub thread_count: Arc<Mutex<Vec<(DateTime<Utc>, usize)>>>,
163    /// Monitoring active flag
164    pub monitoring_active: Arc<Mutex<bool>>,
165}
166
167impl ResourceMonitor {
168    #[must_use]
169    pub fn new() -> Self {
170        Self {
171            memory_usage: Arc::new(Mutex::new(Vec::new())),
172            cpu_usage: Arc::new(Mutex::new(Vec::new())),
173            thread_count: Arc::new(Mutex::new(Vec::new())),
174            monitoring_active: Arc::new(Mutex::new(false)),
175        }
176    }
177
178    /// Start resource monitoring
179    pub fn start_monitoring(&self, interval: Duration) {
180        let memory_usage = self.memory_usage.clone();
181        let cpu_usage = self.cpu_usage.clone();
182        let thread_count = self.thread_count.clone();
183        let active = self.monitoring_active.clone();
184
185        *active.lock().unwrap() = true;
186
187        thread::spawn(move || {
188            while *active.lock().unwrap() {
189                let now = Utc::now();
190
191                // Mock resource monitoring (in real implementation, use system APIs)
192                let memory_mb = Self::get_current_memory_usage();
193                let cpu_percent = Self::get_current_cpu_usage();
194                let threads = Self::get_current_thread_count();
195
196                memory_usage.lock().unwrap().push((now, memory_mb));
197                cpu_usage.lock().unwrap().push((now, cpu_percent));
198                thread_count.lock().unwrap().push((now, threads));
199
200                thread::sleep(interval);
201            }
202        });
203    }
204
205    /// Stop resource monitoring
206    pub fn stop_monitoring(&self) {
207        *self.monitoring_active.lock().unwrap() = false;
208    }
209
210    /// Get current memory usage (mock implementation)
211    fn get_current_memory_usage() -> u64 {
212        // In real implementation, use system APIs to get actual memory usage
213        thread_rng().random::<u64>() % 1024 + 100 // Mock: 100-1124 MB
214    }
215
216    /// Get current CPU usage (mock implementation)
217    fn get_current_cpu_usage() -> f64 {
218        // In real implementation, use system APIs to get actual CPU usage
219        thread_rng().gen_range(0.1..0.9) // Mock: 10-90%
220    }
221
222    /// Get current thread count (mock implementation)
223    fn get_current_thread_count() -> usize {
224        // In real implementation, count actual threads
225        thread_rng().gen_range(1..=20) // Mock: 1-20 threads
226    }
227
228    /// Get memory usage statistics
229    #[must_use]
230    pub fn get_memory_stats(&self) -> ResourceStats {
231        let usage = self.memory_usage.lock().unwrap();
232        if usage.is_empty() {
233            return ResourceStats::default();
234        }
235
236        let values: Vec<f64> = usage.iter().map(|(_, mem)| *mem as f64).collect();
237        ResourceStats::from_values(&values)
238    }
239
240    /// Get CPU usage statistics
241    #[must_use]
242    pub fn get_cpu_stats(&self) -> ResourceStats {
243        let usage = self.cpu_usage.lock().unwrap();
244        if usage.is_empty() {
245            return ResourceStats::default();
246        }
247
248        let values: Vec<f64> = usage.iter().map(|(_, cpu)| *cpu).collect();
249        ResourceStats::from_values(&values)
250    }
251}
252
253impl Default for ResourceMonitor {
254    fn default() -> Self {
255        Self::new()
256    }
257}
258
259/// Resource usage statistics
260#[derive(Debug, Clone, Serialize, Deserialize)]
261pub struct ResourceStats {
262    pub min: f64,
263    pub max: f64,
264    pub mean: f64,
265    pub std_dev: f64,
266    pub percentile_95: f64,
267    pub percentile_99: f64,
268}
269
270impl ResourceStats {
271    fn from_values(values: &[f64]) -> Self {
272        if values.is_empty() {
273            return Self::default();
274        }
275
276        let mut sorted = values.to_vec();
277        sorted.sort_by(|a, b| a.partial_cmp(b).unwrap());
278
279        let min = sorted[0];
280        let max = sorted[sorted.len() - 1];
281        let mean = values.iter().sum::<f64>() / values.len() as f64;
282
283        let variance = values.iter().map(|x| (x - mean).powi(2)).sum::<f64>() / values.len() as f64;
284        let std_dev = variance.sqrt();
285
286        let p95_idx = (0.95 * (sorted.len() - 1) as f64) as usize;
287        let p99_idx = (0.99 * (sorted.len() - 1) as f64) as usize;
288        let percentile_95 = sorted[p95_idx];
289        let percentile_99 = sorted[p99_idx];
290
291        Self {
292            min,
293            max,
294            mean,
295            std_dev,
296            percentile_95,
297            percentile_99,
298        }
299    }
300}
301
302impl Default for ResourceStats {
303    fn default() -> Self {
304        Self {
305            min: 0.0,
306            max: 0.0,
307            mean: 0.0,
308            std_dev: 0.0,
309            percentile_95: 0.0,
310            percentile_99: 0.0,
311        }
312    }
313}
314
315/// Result of a stress test
316#[derive(Debug, Clone, Serialize, Deserialize)]
317pub struct StressTestResult {
318    /// Test scenario
319    pub scenario: StressTestScenario,
320    /// Test success status
321    pub success: bool,
322    /// Execution time
323    pub execution_time: Duration,
324    /// Peak memory usage (MB)
325    pub peak_memory_mb: u64,
326    /// Average CPU usage
327    pub avg_cpu_usage: f64,
328    /// Throughput (operations per second)
329    pub throughput: f64,
330    /// Error count
331    pub error_count: usize,
332    /// Performance degradation factor
333    pub performance_degradation: f64,
334    /// Resource usage statistics
335    pub resource_stats: ResourceUsageStats,
336    /// Detected issues
337    pub issues: Vec<StressTestIssue>,
338    /// Additional metrics
339    pub metrics: HashMap<String, f64>,
340}
341
342/// Resource usage statistics for stress test
343#[derive(Debug, Clone, Serialize, Deserialize)]
344pub struct ResourceUsageStats {
345    pub memory: ResourceStats,
346    pub cpu: ResourceStats,
347    pub max_threads: usize,
348    pub io_operations: u64,
349}
350
351/// Issues detected during stress testing
352#[derive(Debug, Clone, Serialize, Deserialize)]
353pub enum StressTestIssue {
354    /// Memory leak detected
355    MemoryLeak {
356        initial_memory: u64,
357        final_memory: u64,
358        leak_rate_mb_per_sec: f64,
359    },
360    /// Deadlock detected
361    Deadlock {
362        thread_ids: Vec<usize>,
363        duration: Duration,
364    },
365    /// Performance degradation
366    PerformanceDegradation {
367        baseline_time: Duration,
368        actual_time: Duration,
369        degradation_factor: f64,
370    },
371    /// Resource exhaustion
372    ResourceExhaustion {
373        resource_type: String,
374        limit: f64,
375        peak_usage: f64,
376    },
377    /// Error rate spike
378    ErrorRateSpike {
379        baseline_error_rate: f64,
380        actual_error_rate: f64,
381        spike_factor: f64,
382    },
383    /// Timeout
384    Timeout {
385        expected_duration: Duration,
386        actual_duration: Duration,
387    },
388}
389
390impl StressTester {
391    /// Create a new stress tester
392    #[must_use]
393    pub fn new(config: StressTestConfig) -> Self {
394        Self {
395            config,
396            resource_monitor: ResourceMonitor::new(),
397            scenarios: Vec::new(),
398            results: Vec::new(),
399        }
400    }
401
402    /// Add a stress test scenario
403    pub fn add_scenario(&mut self, scenario: StressTestScenario) {
404        self.scenarios.push(scenario);
405    }
406
407    /// Run all stress test scenarios
408    pub fn run_all_tests<T: Estimator + Send + Sync>(&mut self, pipeline: &T) -> SklResult<()> {
409        for scenario in self.scenarios.clone() {
410            let result = self.run_scenario(pipeline, &scenario)?;
411            self.results.push(result);
412        }
413        Ok(())
414    }
415
416    /// Run a specific stress test scenario
417    pub fn run_scenario<T: Estimator + Send + Sync>(
418        &self,
419        pipeline: &T,
420        scenario: &StressTestScenario,
421    ) -> SklResult<StressTestResult> {
422        let start_time = Instant::now();
423
424        // Start resource monitoring
425        self.resource_monitor
426            .start_monitoring(Duration::from_millis(100));
427
428        let mut result = match scenario {
429            StressTestScenario::HighVolumeData {
430                scale_factor,
431                batch_size,
432            } => self.test_high_volume_data(pipeline, *scale_factor, *batch_size)?,
433            StressTestScenario::ConcurrentExecution {
434                num_threads,
435                num_pipelines,
436            } => self.test_concurrent_execution(pipeline, *num_threads, *num_pipelines)?,
437            StressTestScenario::MemoryPressure {
438                target_memory_mb,
439                allocation_pattern,
440            } => self.test_memory_pressure(pipeline, *target_memory_mb, allocation_pattern)?,
441            StressTestScenario::CpuIntensive {
442                complexity_level,
443                computation_type,
444            } => self.test_cpu_intensive(pipeline, *complexity_level, computation_type)?,
445            StressTestScenario::LongRunning {
446                duration,
447                operation_interval,
448            } => self.test_long_running(pipeline, *duration, *operation_interval)?,
449            StressTestScenario::ResourceStarvation {
450                memory_limit_mb,
451                cpu_limit_percent,
452            } => self.test_resource_starvation(pipeline, *memory_limit_mb, *cpu_limit_percent)?,
453            StressTestScenario::EdgeCaseHandling { edge_cases } => {
454                self.test_edge_cases(pipeline, edge_cases)?
455            }
456        };
457
458        // Stop resource monitoring
459        self.resource_monitor.stop_monitoring();
460
461        // Update result with resource statistics
462        result.resource_stats.memory = self.resource_monitor.get_memory_stats();
463        result.resource_stats.cpu = self.resource_monitor.get_cpu_stats();
464        result.execution_time = start_time.elapsed();
465
466        // Detect issues
467        result.issues = self.detect_issues(&result);
468
469        Ok(result)
470    }
471
472    /// Test high volume data processing
473    fn test_high_volume_data<T: Estimator>(
474        &self,
475        _pipeline: &T,
476        scale_factor: f64,
477        _batch_size: usize,
478    ) -> SklResult<StressTestResult> {
479        // Generate large dataset
480        let n_samples = (10000.0 * scale_factor) as usize;
481        let n_features = 100;
482
483        let data = Array2::<f64>::zeros((n_samples, n_features));
484        let _targets = Array1::<f64>::zeros(n_samples);
485
486        // Mock processing
487        thread::sleep(Duration::from_millis((scale_factor * 100.0) as u64));
488
489        Ok(StressTestResult {
490            scenario: StressTestScenario::HighVolumeData {
491                scale_factor,
492                batch_size: _batch_size,
493            },
494            success: true,
495            execution_time: Duration::default(),
496            peak_memory_mb: (n_samples * n_features * 8) as u64 / (1024 * 1024), // Approx memory usage
497            avg_cpu_usage: 0.7,
498            throughput: n_samples as f64 / (scale_factor * 0.1), // Mock throughput
499            error_count: 0,
500            performance_degradation: scale_factor,
501            resource_stats: ResourceUsageStats::default(),
502            issues: Vec::new(),
503            metrics: HashMap::new(),
504        })
505    }
506
507    /// Test concurrent pipeline execution
508    fn test_concurrent_execution<T: Estimator + Send + Sync>(
509        &self,
510        _pipeline: &T,
511        num_threads: usize,
512        num_pipelines: usize,
513    ) -> SklResult<StressTestResult> {
514        let handles = (0..num_threads)
515            .map(|_| {
516                thread::spawn(move || {
517                    for _ in 0..num_pipelines {
518                        // Mock pipeline execution
519                        thread::sleep(Duration::from_millis(10));
520                    }
521                })
522            })
523            .collect::<Vec<_>>();
524
525        for handle in handles {
526            handle.join().unwrap();
527        }
528
529        Ok(StressTestResult {
530            scenario: StressTestScenario::ConcurrentExecution {
531                num_threads,
532                num_pipelines,
533            },
534            success: true,
535            execution_time: Duration::default(),
536            peak_memory_mb: (num_threads * num_pipelines * 10) as u64, // Mock memory usage
537            avg_cpu_usage: 0.8,
538            throughput: (num_threads * num_pipelines) as f64,
539            error_count: 0,
540            performance_degradation: 1.2,
541            resource_stats: ResourceUsageStats::default(),
542            issues: Vec::new(),
543            metrics: HashMap::new(),
544        })
545    }
546
547    /// Test memory pressure scenarios
548    fn test_memory_pressure<T: Estimator>(
549        &self,
550        _pipeline: &T,
551        target_memory_mb: u64,
552        _pattern: &MemoryPattern,
553    ) -> SklResult<StressTestResult> {
554        // Allocate memory to create pressure
555        let mut _memory_hogs: Vec<Vec<u8>> = Vec::new();
556        let chunk_size = 1024 * 1024; // 1MB chunks
557
558        for _ in 0..(target_memory_mb as usize) {
559            _memory_hogs.push(vec![0u8; chunk_size]);
560        }
561
562        // Mock processing under memory pressure
563        thread::sleep(Duration::from_millis(500));
564
565        Ok(StressTestResult {
566            scenario: StressTestScenario::MemoryPressure {
567                target_memory_mb,
568                allocation_pattern: _pattern.clone(),
569            },
570            success: true,
571            execution_time: Duration::default(),
572            peak_memory_mb: target_memory_mb,
573            avg_cpu_usage: 0.5,
574            throughput: 100.0 / (target_memory_mb as f64 / 1000.0), // Inverse relationship
575            error_count: 0,
576            performance_degradation: target_memory_mb as f64 / 1000.0,
577            resource_stats: ResourceUsageStats::default(),
578            issues: Vec::new(),
579            metrics: HashMap::new(),
580        })
581    }
582
583    /// Test CPU intensive operations
584    fn test_cpu_intensive<T: Estimator>(
585        &self,
586        _pipeline: &T,
587        complexity_level: usize,
588        _computation_type: &ComputationType,
589    ) -> SklResult<StressTestResult> {
590        // Perform CPU intensive computation
591        let mut result = 0.0;
592        for i in 0..(complexity_level * 10000) {
593            result += (i as f64).sin().cos().tan();
594        }
595
596        Ok(StressTestResult {
597            scenario: StressTestScenario::CpuIntensive {
598                complexity_level,
599                computation_type: _computation_type.clone(),
600            },
601            success: true,
602            execution_time: Duration::default(),
603            peak_memory_mb: 50, // Low memory usage
604            avg_cpu_usage: 0.95,
605            throughput: complexity_level as f64,
606            error_count: 0,
607            performance_degradation: complexity_level as f64 / 10.0,
608            resource_stats: ResourceUsageStats::default(),
609            issues: Vec::new(),
610            metrics: HashMap::from([("computation_result".to_string(), result)]),
611        })
612    }
613
614    /// Test long running stability
615    fn test_long_running<T: Estimator>(
616        &self,
617        _pipeline: &T,
618        duration: Duration,
619        operation_interval: Duration,
620    ) -> SklResult<StressTestResult> {
621        let start = Instant::now();
622        let mut operations = 0;
623
624        while start.elapsed() < duration {
625            // Mock operation
626            thread::sleep(operation_interval);
627            operations += 1;
628        }
629
630        Ok(StressTestResult {
631            scenario: StressTestScenario::LongRunning {
632                duration,
633                operation_interval,
634            },
635            success: true,
636            execution_time: start.elapsed(),
637            peak_memory_mb: 100,
638            avg_cpu_usage: 0.3,
639            throughput: f64::from(operations) / duration.as_secs_f64(),
640            error_count: 0,
641            performance_degradation: 1.0,
642            resource_stats: ResourceUsageStats::default(),
643            issues: Vec::new(),
644            metrics: HashMap::from([("total_operations".to_string(), f64::from(operations))]),
645        })
646    }
647
648    /// Test resource starvation scenarios
649    fn test_resource_starvation<T: Estimator>(
650        &self,
651        _pipeline: &T,
652        memory_limit_mb: u64,
653        _cpu_limit_percent: f64,
654    ) -> SklResult<StressTestResult> {
655        // Mock resource-constrained execution
656        thread::sleep(Duration::from_millis(200));
657
658        Ok(StressTestResult {
659            scenario: StressTestScenario::ResourceStarvation {
660                memory_limit_mb,
661                cpu_limit_percent: _cpu_limit_percent,
662            },
663            success: true,
664            execution_time: Duration::default(),
665            peak_memory_mb: memory_limit_mb,
666            avg_cpu_usage: _cpu_limit_percent,
667            throughput: 50.0,
668            error_count: 0,
669            performance_degradation: 2.0,
670            resource_stats: ResourceUsageStats::default(),
671            issues: Vec::new(),
672            metrics: HashMap::new(),
673        })
674    }
675
676    /// Test edge case handling
677    fn test_edge_cases<T: Estimator>(
678        &self,
679        _pipeline: &T,
680        edge_cases: &[EdgeCase],
681    ) -> SklResult<StressTestResult> {
682        let total_errors = 0;
683
684        for edge_case in edge_cases {
685            match edge_case {
686                EdgeCase::EmptyData => {
687                    // Test with empty dataset
688                    let _empty_data = Array2::<f64>::zeros((0, 10));
689                }
690                EdgeCase::SingleSample => {
691                    // Test with single sample
692                    let _single_data = Array2::<f64>::zeros((1, 10));
693                }
694                EdgeCase::HighDimensional { dimensions } => {
695                    // Test with high dimensional data
696                    let _high_dim_data = Array2::<f64>::zeros((100, *dimensions));
697                }
698                EdgeCase::IdenticalValues => {
699                    // Test with identical values
700                    let _identical_data = Array2::<f64>::ones((100, 10));
701                }
702                EdgeCase::ExtremeOutliers {
703                    outlier_magnitude: _,
704                } => {
705                    // Test with extreme outliers
706                    let mut data = Array2::<f64>::zeros((100, 10));
707                    data[[0, 0]] = 1e10; // Extreme outlier
708                }
709                EdgeCase::MissingValues { missing_ratio: _ } => {
710                    // Test with missing values (NaN)
711                    let mut data = Array2::<f64>::zeros((100, 10));
712                    data[[0, 0]] = f64::NAN;
713                }
714                EdgeCase::HighlyCorrelated { correlation: _ } => {
715                    // Test with highly correlated features
716                    let _corr_data = Array2::<f64>::zeros((100, 10));
717                }
718                EdgeCase::NumericalEdges => {
719                    // Test numerical edge cases
720                    let mut data = Array2::<f64>::zeros((10, 3));
721                    data[[0, 0]] = f64::INFINITY;
722                    data[[1, 0]] = f64::NEG_INFINITY;
723                    data[[2, 0]] = f64::MIN;
724                    data[[3, 0]] = f64::MAX;
725                }
726            }
727        }
728
729        Ok(StressTestResult {
730            scenario: StressTestScenario::EdgeCaseHandling {
731                edge_cases: edge_cases.to_vec(),
732            },
733            success: total_errors == 0,
734            execution_time: Duration::default(),
735            peak_memory_mb: 100,
736            avg_cpu_usage: 0.4,
737            throughput: edge_cases.len() as f64,
738            error_count: total_errors,
739            performance_degradation: 1.1,
740            resource_stats: ResourceUsageStats::default(),
741            issues: Vec::new(),
742            metrics: HashMap::from([("edge_cases_tested".to_string(), edge_cases.len() as f64)]),
743        })
744    }
745
746    /// Detect issues in stress test results
747    fn detect_issues(&self, result: &StressTestResult) -> Vec<StressTestIssue> {
748        let mut issues = Vec::new();
749
750        // Check for performance degradation
751        if result.performance_degradation > self.config.performance_threshold {
752            issues.push(StressTestIssue::PerformanceDegradation {
753                baseline_time: Duration::from_secs(1), // Mock baseline
754                actual_time: result.execution_time,
755                degradation_factor: result.performance_degradation,
756            });
757        }
758
759        // Check for memory leaks (mock detection)
760        if self.config.detect_memory_leaks && result.peak_memory_mb > 1000 {
761            issues.push(StressTestIssue::MemoryLeak {
762                initial_memory: 100,
763                final_memory: result.peak_memory_mb,
764                leak_rate_mb_per_sec: (result.peak_memory_mb - 100) as f64
765                    / result.execution_time.as_secs_f64(),
766            });
767        }
768
769        // Check for resource exhaustion
770        if result.peak_memory_mb > self.config.memory_limit_mb {
771            issues.push(StressTestIssue::ResourceExhaustion {
772                resource_type: "memory".to_string(),
773                limit: self.config.memory_limit_mb as f64,
774                peak_usage: result.peak_memory_mb as f64,
775            });
776        }
777
778        // Check for high error rates
779        if result.error_count > 0 {
780            let error_rate = result.error_count as f64 / result.throughput;
781            if error_rate > self.config.error_tolerance {
782                issues.push(StressTestIssue::ErrorRateSpike {
783                    baseline_error_rate: 0.0,
784                    actual_error_rate: error_rate,
785                    spike_factor: error_rate / self.config.error_tolerance,
786                });
787            }
788        }
789
790        issues
791    }
792
793    /// Generate comprehensive stress test report
794    #[must_use]
795    pub fn generate_report(&self) -> StressTestReport {
796        let total_tests = self.results.len();
797        let successful_tests = self.results.iter().filter(|r| r.success).count();
798        let failed_tests = total_tests - successful_tests;
799
800        let avg_execution_time = if self.results.is_empty() {
801            0.0
802        } else {
803            self.results
804                .iter()
805                .map(|r| r.execution_time.as_secs_f64())
806                .sum::<f64>()
807                / self.results.len() as f64
808        };
809
810        let peak_memory_usage = self
811            .results
812            .iter()
813            .map(|r| r.peak_memory_mb)
814            .max()
815            .unwrap_or(0);
816
817        let all_issues: Vec<_> = self
818            .results
819            .iter()
820            .flat_map(|r| r.issues.iter().cloned())
821            .collect();
822
823        StressTestReport {
824            timestamp: Utc::now(),
825            config: self.config.clone(),
826            total_tests,
827            successful_tests,
828            failed_tests,
829            avg_execution_time: Duration::from_secs_f64(avg_execution_time),
830            peak_memory_usage,
831            detected_issues: all_issues,
832            results: self.results.clone(),
833            recommendations: self.generate_recommendations(),
834        }
835    }
836
837    /// Generate recommendations based on test results
838    fn generate_recommendations(&self) -> Vec<String> {
839        let mut recommendations = Vec::new();
840
841        // Analyze performance issues
842        let performance_issues = self
843            .results
844            .iter()
845            .filter(|r| r.performance_degradation > self.config.performance_threshold)
846            .count();
847
848        if performance_issues > 0 {
849            recommendations.push(format!(
850                "Performance degradation detected in {performance_issues} tests. Consider optimizing algorithms or increasing resources."
851            ));
852        }
853
854        // Analyze memory usage
855        let high_memory_tests = self
856            .results
857            .iter()
858            .filter(|r| r.peak_memory_mb > self.config.memory_limit_mb)
859            .count();
860
861        if high_memory_tests > 0 {
862            recommendations.push(format!(
863                "Memory limit exceeded in {high_memory_tests} tests. Consider implementing memory optimization strategies."
864            ));
865        }
866
867        // Analyze error rates
868        let error_tests = self.results.iter().filter(|r| r.error_count > 0).count();
869
870        if error_tests > 0 {
871            recommendations.push(format!(
872                "Errors detected in {error_tests} tests. Review error handling and edge case management."
873            ));
874        }
875
876        if recommendations.is_empty() {
877            recommendations.push(
878                "All stress tests passed successfully. Pipeline shows good stability under load."
879                    .to_string(),
880            );
881        }
882
883        recommendations
884    }
885}
886
887impl Default for ResourceUsageStats {
888    fn default() -> Self {
889        Self {
890            memory: ResourceStats::default(),
891            cpu: ResourceStats::default(),
892            max_threads: 1,
893            io_operations: 0,
894        }
895    }
896}
897
898/// Comprehensive stress test report
899#[derive(Debug, Clone, Serialize, Deserialize)]
900pub struct StressTestReport {
901    pub timestamp: DateTime<Utc>,
902    pub config: StressTestConfig,
903    pub total_tests: usize,
904    pub successful_tests: usize,
905    pub failed_tests: usize,
906    pub avg_execution_time: Duration,
907    pub peak_memory_usage: u64,
908    pub detected_issues: Vec<StressTestIssue>,
909    pub results: Vec<StressTestResult>,
910    pub recommendations: Vec<String>,
911}
912
913#[allow(non_snake_case)]
914#[cfg(test)]
915mod tests {
916    use super::*;
917    use scirs2_core::ndarray::Array2;
918    use sklears_core::error::SklearsError;
919
920    // Mock estimator for testing
921    struct MockEstimator;
922
923    impl Estimator for MockEstimator {
924        type Config = ();
925        type Error = SklearsError;
926        type Float = f64;
927
928        fn config(&self) -> &Self::Config {
929            &()
930        }
931    }
932
933    #[test]
934    fn test_stress_tester_creation() {
935        let config = StressTestConfig::default();
936        let tester = StressTester::new(config);
937        assert_eq!(tester.scenarios.len(), 0);
938        assert_eq!(tester.results.len(), 0);
939    }
940
941    #[test]
942    fn test_add_scenario() {
943        let config = StressTestConfig::default();
944        let mut tester = StressTester::new(config);
945
946        let scenario = StressTestScenario::HighVolumeData {
947            scale_factor: 10.0,
948            batch_size: 1000,
949        };
950
951        tester.add_scenario(scenario);
952        assert_eq!(tester.scenarios.len(), 1);
953    }
954
955    #[test]
956    fn test_high_volume_data_scenario() {
957        let config = StressTestConfig::default();
958        let tester = StressTester::new(config);
959        let estimator = MockEstimator;
960
961        let result = tester.test_high_volume_data(&estimator, 5.0, 1000).unwrap();
962        assert!(result.success);
963        assert_eq!(result.performance_degradation, 5.0);
964    }
965
966    #[test]
967    fn test_resource_monitor() {
968        let monitor = ResourceMonitor::new();
969
970        monitor.start_monitoring(Duration::from_millis(1));
971        thread::sleep(Duration::from_millis(10));
972        monitor.stop_monitoring();
973
974        let memory_stats = monitor.get_memory_stats();
975        assert!(memory_stats.min >= 0.0);
976    }
977
978    #[test]
979    fn test_edge_case_handling() {
980        let config = StressTestConfig::default();
981        let tester = StressTester::new(config);
982        let estimator = MockEstimator;
983
984        let edge_cases = vec![
985            EdgeCase::EmptyData,
986            EdgeCase::SingleSample,
987            EdgeCase::NumericalEdges,
988        ];
989
990        let result = tester.test_edge_cases(&estimator, &edge_cases).unwrap();
991        assert!(result.success);
992        assert_eq!(result.error_count, 0);
993    }
994
995    #[test]
996    fn test_issue_detection() {
997        let config = StressTestConfig {
998            performance_threshold: 2.0,
999            memory_limit_mb: 500,
1000            ..Default::default()
1001        };
1002        let tester = StressTester::new(config);
1003
1004        let result = StressTestResult {
1005            scenario: StressTestScenario::HighVolumeData {
1006                scale_factor: 1.0,
1007                batch_size: 100,
1008            },
1009            success: true,
1010            execution_time: Duration::from_secs(5),
1011            peak_memory_mb: 1000, // Exceeds limit
1012            avg_cpu_usage: 0.8,
1013            throughput: 100.0,
1014            error_count: 0,
1015            performance_degradation: 3.0, // Exceeds threshold
1016            resource_stats: ResourceUsageStats::default(),
1017            issues: Vec::new(),
1018            metrics: HashMap::new(),
1019        };
1020
1021        let issues = tester.detect_issues(&result);
1022        assert!(!issues.is_empty());
1023
1024        // Should detect both performance degradation and resource exhaustion
1025        let has_performance_issue = issues
1026            .iter()
1027            .any(|issue| matches!(issue, StressTestIssue::PerformanceDegradation { .. }));
1028        let has_resource_issue = issues
1029            .iter()
1030            .any(|issue| matches!(issue, StressTestIssue::ResourceExhaustion { .. }));
1031
1032        assert!(has_performance_issue);
1033        assert!(has_resource_issue);
1034    }
1035
1036    #[test]
1037    fn test_generate_report() {
1038        let config = StressTestConfig::default();
1039        let mut tester = StressTester::new(config);
1040
1041        // Add some mock results
1042        tester.results.push(StressTestResult {
1043            scenario: StressTestScenario::HighVolumeData {
1044                scale_factor: 1.0,
1045                batch_size: 100,
1046            },
1047            success: true,
1048            execution_time: Duration::from_secs(2),
1049            peak_memory_mb: 200,
1050            avg_cpu_usage: 0.5,
1051            throughput: 100.0,
1052            error_count: 0,
1053            performance_degradation: 1.0,
1054            resource_stats: ResourceUsageStats::default(),
1055            issues: Vec::new(),
1056            metrics: HashMap::new(),
1057        });
1058
1059        let report = tester.generate_report();
1060        assert_eq!(report.total_tests, 1);
1061        assert_eq!(report.successful_tests, 1);
1062        assert_eq!(report.failed_tests, 0);
1063        assert!(!report.recommendations.is_empty());
1064    }
1065}