تصميم التوافر العالي
في هذه الصفحة 9 موضوعات
نص الدروس والتمارين باللغة الإنجليزية، بينما تبقى واجهة الموقع وعناوين الدروس بالعربية.
نظرة عامة
الموضوعات
- التكرار (Redundancy)
- التخلص من الحمل (load shedding)
- التحويل عند الفشل (failover)
- احتواء الأعطال
تعلّم أولًا
3.5 ساعة تدريب (تقدير)
مخرجات التعلم
- Design redundancy at every layer and remove hidden single points of failure.
- Apply load shedding, admission control, and prioritization under overload.
- Contain faults with cells, shuffle sharding, and bulkheads at the infrastructure level.
- Compute composite availability and explain why dependencies cap it.
الدروس
المختبر والتمارين
Lab
SRB-005-LAB1 · Availability budget
Outcomes: 1, 2, 3, 4 · Time: ~3.5 h
- Map checkout dependencies including FulfillCo ones and mark hard or soft.
- Compute composite availability with measured figures.
- Redesign (fallbacks, cells, bulkheads) to reach 99.95%.
- Run a load-shedding experiment and record results.
Acceptance: math shown; load-shedding experiment run with before/after numbers.
Exercises
| ID | Outcome | Task |
|---|---|---|
| SRB-005-EX01 | 4 | Compute checkout availability: 99.95%, 99.99%, 99.9%, 99.9% in series. |
| SRB-005-EX02 | 4 | Recompute when the 99.9% stock check gets a cache fallback that serves 90% of failures. |
| SRB-005-EX03 | 1 | Audit a design for hidden SPOFs and list five. |
| SRB-005-EX04 | 2 | Write the shedding priority policy for the flash sale. |
| SRB-005-EX05 | 3 | Propose a cell design for FulfillCo shipping and the routing key. |
| SRB-005-EX06 | 3 | Explain shuffle sharding to a teammate with numbers. |
أظهر الحلول
- EX01 Product about 99.74%; below 99.95% so redesign needed.
- EX02 Effective stock failure drops to 0.01%, so about 99.99%; total about 99.83%; show the arithmetic.
- EX03 Certificate expiry, shared config, single DNS provider, single CI pipeline, one on-call expert.
- EX04 Protect payment confirmation and checkout of logged-in users; throttle browse; drop crawlers and recommendations first.
- EX05 Cells by warehouse region with routing by warehouse id; rollouts cell by cell.
- EX06 8 workers, 2 per customer: 28 pairs; chance two share both is 1/28.
Workplace evidence: an availability improvement you designed with before/after numbers.
الاختبار
Outcomes: O1 redundancy and SPOFs · O2 shedding · O3 fault containment · O4 availability math.
اختبار ذاتي لك: لا توجد درجات، ولا يُحفظ أو يُرسل أي شيء. اختر إجابة ثم تحقق منها، ويمكنك المحاولة مرة أخرى كما تشاء.
الجزء العملي
Availability calculation problems (series, parallel, fallback) plus the lab's experiment evidence. Pass: 70% on the quiz and correct math in the lab.
أخطاء شائعة
Multiplying nines without dependency analysis; shedding that drops paying customers first.
التقييم
Availability calculation problems.
دليل من بيئة العمل
An availability improvement you designed with before/after numbers.
الصلة بالمسار الوظيفي
Enterprise resilience (SRA-006).