Initial commit: Complete Software Architecture course with 11 modules

- Added comprehensive course structure with 11 modules
- Included theoretical content, practical examples, and tasks
- Multi-language code examples (Java, Rust, Node.js, Python)
- Detailed analysis of architectural approaches and trade-offs
- Complete caching strategies documentation
- Architecture examples from real-world systems (Twitter, Netflix, Uber)
- Structured navigation and learning path
- Ready for educational use

modules/module5/sections/07-sli-slo-sla.md

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+# SLI/SLO/SLA
+
+## Навигация
+- [🏠 Главная страница курса](../../../README.md)
+- [📚 Модуль 5](../README.md)
+
+---
+
+## SLI (Индикатор уровня сервиса)
+
+**SLI** — метрика, которая измеряет качество сервиса.
+
+### Примеры SLI:
+- **Availability**: `successful_requests / total_requests`
+- **Latency**: `requests_completed_within_threshold / total_requests`
+- **Throughput**: `successful_requests_per_second`
+
+```java
+@Component
+public class SLICalculator {
+    public double calculateAvailability(String service, Duration window) {
+        Counter successfulRequests = Counter.builder("requests.successful")
+            .tag("service", service)
+            .register(meterRegistry);
+            
+        Counter totalRequests = Counter.builder("requests.total")
+            .tag("service", service)
+            .register(meterRegistry);
+            
+        double successful = successfulRequests.count();
+        double total = totalRequests.count();
+        
+        return total > 0 ? successful / total : 0.0;
+    }
+    
+    public double calculateLatency(String service, Duration threshold) {
+        Timer requestTimer = Timer.builder("request.duration")
+            .tag("service", service)
+            .register(meterRegistry);
+            
+        // логика расчета латентности
+        return 0.95; // пример
+    }
+}
+```
+
+## SLO (Цель уровня сервиса)
+
+**SLO** — целевое значение для SLI.
+
+### Примеры SLO:
+- **Availability**: 99.9% uptime
+- **Latency**: 95% of requests < 200ms
+- **Error Rate**: < 0.1% errors
+
+```java
+@Component
+public class SLOMonitor {
+    private final Map<String, SLO> slos = Map.of(
+        "availability", new SLO("availability", 0.999, "99.9% uptime"),
+        "latency", new SLO("latency", 0.95, "95% < 200ms"),
+        "error_rate", new SLO("error_rate", 0.001, "< 0.1% errors")
+    );
+    
+    public boolean checkSLO(String sloName, double currentValue) {
+        SLO slo = slos.get(sloName);
+        return currentValue >= slo.getTarget();
+    }
+}
+```
+
+## SLA (Соглашение об уровне сервиса)
+
+**SLA** — соглашение с клиентами о качестве сервиса.
+
+### Компоненты SLA:
+- **Service Description** — описание сервиса
+- **Performance Metrics** — метрики производительности
+- **Availability Targets** — цели доступности
+- **Remediation** — меры по устранению нарушений