Add CLOUD_SYSTEM_ARCHITECTURE.md

CLOUD_SYSTEM_ARCHITECTURE.md

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+# Cloud System Architecture (Non-HA)
+
+## Overview
+
+This document describes the architecture of the cloud-hosted application environment.
+The system is designed as a **single primary cloud deployment without high availability**, with **external access over the internet** and **backup protection managed by CBM**.
+
+This design prioritizes:
+
+* simplicity
+* lower infrastructure cost
+* straightforward deployment
+* reliable offsite backups
+
+High availability and automatic failover are **not implemented** in this architecture.
+
+---
+
+# Architecture Overview
+
+```mermaid
+flowchart TB
+
+A[Users]
+
+B[Internet]
+
+C[Cloud Application Server]
+
+D[(Primary Database)]
+
+E[CBM Backup System]
+
+A --> B
+B --> C
+C --> D
+
+C --> E
+D --> E
+```
+
+### Components
+
+| Component                | Description                                             |
+| ------------------------ | ------------------------------------------------------- |
+| Users                    | Employees or authorized users accessing the application |
+| Internet                 | Public internet connection used to access the system    |
+| Cloud Application Server | Hosts the web application                               |
+| Primary Database         | Stores application data                                 |
+| CBM Backup System        | Performs scheduled backups for disaster recovery        |
+
+---
+
+# System Access
+
+The application is accessed externally via a domain name.
+
+Example:
+
+```
+https://app.companydomain.com
+```
+
+Traffic flow:
+
+```mermaid
+flowchart LR
+
+USER[User Device]
+
+INT[Internet]
+
+APP[Cloud Application Server]
+
+DB[(Database)]
+
+USER --> INT
+INT --> APP
+APP --> DB
+```
+
+### Authentication
+
+Access to the system may be restricted through:
+
+* application login authentication
+* IP allow lists
+* HTTPS encryption
+
+---
+
+# Infrastructure Components
+
+## Cloud Application Server
+
+The cloud server hosts:
+
+* the web application
+* API services
+* connection to the database
+
+Typical responsibilities:
+
+* processing user requests
+* serving application content
+* interacting with the database
+
+---
+
+## Primary Database
+
+The database stores:
+
+* application records
+* inventory or operational data
+* user information
+* system configuration data
+
+The database resides **on the same cloud infrastructure environment** as the application server.
+
+---
+
+# Backup System
+
+All backups are managed through **CBM**.
+
+```mermaid
+flowchart LR
+
+APP[Application Server]
+
+DB[(Database)]
+
+BACKUP[CBM Backup Storage]
+
+APP --> BACKUP
+DB --> BACKUP
+```
+
+Backups include:
+
+* full database backups
+* application server snapshots
+* file storage backups (if applicable)
+
+### Backup Schedule
+
+Typical configuration:
+
+| Backup Type      | Frequency             |
+| ---------------- | --------------------- |
+| Database Backup  | Daily                 |
+| Server Snapshot  | Daily                 |
+| Backup Retention | Defined by CBM policy |
+
+Backups are stored **offsite to protect against data loss**.
+
+---
+
+# Disaster Recovery
+
+In the event of system failure:
+
+1. CBM restores the most recent backup.
+2. The cloud server environment is rebuilt if necessary.
+3. The application and database are restored.
+4. Services are brought back online.
+
+Recovery time will depend on:
+
+* backup size
+* restoration process
+* infrastructure rebuild time
+
+---
+
+# Limitations of This Architecture
+
+Because this system is **not high availability**, the following conditions may cause downtime:
+
+| Event                               | Result                       |
+| ----------------------------------- | ---------------------------- |
+| Cloud server failure                | Application unavailable      |
+| Cloud maintenance                   | Temporary downtime possible  |
+| Database corruption                 | Restore from backup required |
+| Internet outage at hosting provider | System unreachable           |
+
+---
+
+# Future Upgrade Path
+
+If higher reliability is required, the architecture can be expanded to include:
+
+* cloud load balancers
+* multiple application servers
+* database replication
+* on-premise failover
+* automated health monitoring
+
+These upgrades would transition the system into a **high availability system**.