# 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**.