Alexander Abakumov
15e744da49
- 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
81 lines
2.6 KiB
Markdown
81 lines
2.6 KiB
Markdown
# SLI/SLO/SLA
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## Навигация
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- [🏠 Главная страница курса](../../../README.md)
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- [📚 Модуль 5](../README.md)
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---
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## SLI (Индикатор уровня сервиса)
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**SLI** — метрика, которая измеряет качество сервиса.
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### Примеры SLI:
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- **Availability**: `successful_requests / total_requests`
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- **Latency**: `requests_completed_within_threshold / total_requests`
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- **Throughput**: `successful_requests_per_second`
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```java
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@Component
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public class SLICalculator {
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public double calculateAvailability(String service, Duration window) {
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Counter successfulRequests = Counter.builder("requests.successful")
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.tag("service", service)
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.register(meterRegistry);
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Counter totalRequests = Counter.builder("requests.total")
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.tag("service", service)
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.register(meterRegistry);
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double successful = successfulRequests.count();
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double total = totalRequests.count();
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return total > 0 ? successful / total : 0.0;
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}
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public double calculateLatency(String service, Duration threshold) {
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Timer requestTimer = Timer.builder("request.duration")
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.tag("service", service)
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.register(meterRegistry);
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// логика расчета латентности
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return 0.95; // пример
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}
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}
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```
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## SLO (Цель уровня сервиса)
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**SLO** — целевое значение для SLI.
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### Примеры SLO:
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- **Availability**: 99.9% uptime
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- **Latency**: 95% of requests < 200ms
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- **Error Rate**: < 0.1% errors
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```java
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@Component
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public class SLOMonitor {
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private final Map<String, SLO> slos = Map.of(
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"availability", new SLO("availability", 0.999, "99.9% uptime"),
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"latency", new SLO("latency", 0.95, "95% < 200ms"),
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"error_rate", new SLO("error_rate", 0.001, "< 0.1% errors")
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);
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public boolean checkSLO(String sloName, double currentValue) {
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SLO slo = slos.get(sloName);
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return currentValue >= slo.getTarget();
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}
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}
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```
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## SLA (Соглашение об уровне сервиса)
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**SLA** — соглашение с клиентами о качестве сервиса.
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### Компоненты SLA:
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- **Service Description** — описание сервиса
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- **Performance Metrics** — метрики производительности
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- **Availability Targets** — цели доступности
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- **Remediation** — меры по устранению нарушений
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