Comic 09 – The Single Point of Failure

When your entire system stands on one shaky box 🧱💥

🧩 Problem

In system design, everything can look perfect on paper:
👉 Clean architecture
👉 Multiple services
👉 Green dashboards

But there’s one silent killer hiding underneath:
a Single Point of Failure (SPOF).

If one component goes down and the entire system collapses…
you didn’t build a distributed system —
you built a fragile one.

💻 Code Example (Conceptual – Single Server)

// A simplified representation of a single-server backend

Server prodServer("Prod-Server-1");

int main() {
    while (true) {
        Request req = receiveRequest();
        prodServer.handle(req); // everything goes here
    }
}

Looks simple. Works locally. Works in testing.

Until Prod-Server-1 goes down.

🌍 Real-World Connection

Imagine an e-commerce platform:

  • User login
  • Product search
  • Payments
  • Notifications

All routed through one backend server.

As traffic grows:

  • CPU spikes
  • Memory fills
  • Latency increases

Then one bad deploy… 💥 The server crashes

Result:

  • No logins
  • No payments
  • No orders
  • No revenue

The business doesn’t degrade — it stops.

🛠 How It’s Solved in the Real World

Real production systems are designed to assume failure, not avoid it.

  • Redundancy Never rely on one instance. Use multiple servers running the same service.

  • Load Balancers Incoming traffic is distributed across healthy servers. If one fails, traffic is rerouted automatically.

  • Replication Databases are replicated across nodes. If the primary goes down, a replica takes over.

  • Health Checks & Auto-Healing Systems constantly check server health. Failed instances are removed and replaced automatically.

  • Failover Strategies Critical services have backups ready to take control within seconds.

In short:

Production systems are built to survive failure — not pretend it won’t happen.

⚡ Takeaway

System design isn’t about making things work. It’s about making sure they keep working when things break.

👉 If one server can take down your system, you don’t have high availability — you have false confidence.

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📅 Published: September 2025 ✍️ Author: Aisha Karigar