Distributed Computing: A Guide For Technicians, Engineers, System Architects, And OT/ICS Professionals

The cloud has become a widely accepted metaphor, abstracting complexity and centralizing workloads. However, newer terms like fog computing, edge computing, mist computing, dew computing, and fluid computing have emerged, especially in industrial automation and control systems. These “moisture metaphors” may sound confusing, but they represent real distributed computing layers that align with the Purdue Model for industrial control systems (ICS).

For those working with PLCs, RTUs, sensors, DCSs, or SCADA, these concepts are not entirely new—they’ve been part of OT (Operational Technology) environments long before cloud computing gave them trendy names.

🔗 Read the full article here: Distributed Computing Guide

You Should Know:

Key Differences Between Cloud, Fog, and Edge Computing

– Cloud Computing: Centralized data processing in remote data centers.
– Fog Computing: Decentralized processing closer to the data source (e.g., routers, gateways).
– Edge Computing: Ultra-low-latency processing directly on devices (e.g., sensors, PLCs).

2. Practical Commands & Tools for Distributed Computing

Linux (IoT/Edge Devices)

Monitor edge device resources 
top 
htop 
df -h  Check disk usage 
free -m  Check memory usage

Network latency test 
ping <fog-gateway-IP> 
traceroute <cloud-server-IP>

Windows (SCADA/DCS Systems)

Check active network connections 
netstat -ano

Test connectivity to fog nodes 
Test-NetConnection -ComputerName <fog-node-IP> -Port <port>

Industrial Protocols (Modbus, OPC UA)

Use nmap to scan for open Modbus ports 
nmap -p 502 --script modbus-discover <target-IP>

Simulate OPC UA client (Python) 
pip install opcua

3. Security Best Practices for OT/ICS

Segment networks using firewalls:

iptables -A INPUT -p tcp --dport 502 -j DROP  Block unauthorized Modbus

Monitor anomalies with tools like Wireshark:
```
wireshark -k -i eth0 -Y "modbus" 
```

What Undercode Say:

Distributed computing is reshaping industrial automation, but security remains critical. Always:
✔ Isolate OT networks from IT using VLANs or physical separation.
✔ Patch legacy systems—many ICS devices run outdated OS.
✔ Log everything—use SIEM tools (Splunk, Graylog) for OT traffic analysis.

For deeper insights, explore the Purdue Model and how it maps to modern architectures.