adding task files

q4-scalability/calculations.md

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+# Scalability and Load Balancing
+
+## 1. Container Calculation
+
+### Given
+
+- Expected traffic: **15,000 requests/second**
+- One container capacity: **500 requests/second**
+- Safety margin: **30%**
+
+### Step 1: Base Number of Containers
+
+15000 / 500 = **30 containers**
+
+### Step 2: Add Safety Margin
+
+30 × 1.30 = **39 containers**
+
+### Final Result
+
+**39 containers** are required to safely handle 15,000 requests per second while maintaining a 30% capacity margin for traffic spikes and failover scenarios.
+
+---
+
+# 2. Cold Start Strategy
+
+To minimize startup latency for new containers:
+
+- Keep a small pool of warm containers ready to receive traffic.
+- Use Kubernetes Horizontal Pod Autoscaler (HPA).
+- Pre-pull container images on worker nodes.
+- Configure Readiness Probes before accepting requests.
+- Use Rolling Updates for zero-downtime deployments.
+- Scale based on CPU utilization and request rate.
+
+---
+
+# 3. Ghaymah Block Storage for Stateful Workloads
+
+Containers are ephemeral and lose local storage when restarted. Stateful workloads require persistent storage.
+
+Ghaymah Block Storage provides persistent volumes that remain attached to applications even after pod or container recreation.
+
+Typical stateful workloads include:
+
+- PostgreSQL
+- MySQL
+- MongoDB
+- Redis Persistence
+- Elasticsearch
+- Jenkins
+- Kafka
+- RabbitMQ
+
+Benefits:
+
+- Persistent storage
+- High performance
+- Volume reattachment after restart
+- Snapshot support
+- Backup and disaster recovery
+- Independent lifecycle from containers
+
+---
+
+# Summary
+
+| Requirement | Solution |
+|------------|----------|
+| Incoming Traffic | 15,000 req/s |
+| Container Capacity | 500 req/s |
+| Safety Margin | 30% |
+| Required Containers | **39 Containers** |
+| Cold Start | Warm Pool, HPA, Image Pre-Pulling, Readiness Probes |