I Misunderstood Scalability in a Distributed System
“Is the application scalable?” asked the manager. It was almost halfway through the weekly system roadmap meeting. I thought we were done with all the tech parts and would soon move to business-related questions.
The architect of my team cleared his throat and answered, “It can easily handle double the usual load.”
The manager gave a long look as if he didn’t believe the answer. But, in the absence of any better points, he continued with further updates. I implicitly believed that our system is indeed scalable. After all, the architect had announced it in clear terms.
A year down the line, I learned the truth. One fine day, the system crashed due to excessive load.
The bank had launched a new loan product for the holiday season. The business strategy paid off and there was a surge in demand. Since our application provided the core data to make the credit decision, it was swamped with 5 times more incoming requests from several other applications.