Example: inventory updates
Imagine many customers buying the same product. One update owns the inventory row while every other worker waits behind it.
Interactive Systems Explainers
Lock Contention Playground
See how multiple workers accessing the same resource can block concurrent work.
Related Concepts
Key Observations
What to Notice
Hot Resources
Some rows receive most of the traffic. The hot row glows while nearby rows sit mostly free.
Blocked Work
A locked row only has one owner. Extra workers stop helping once they are all waiting for the same lock.
Convoy Effects
One slow update holds the lock longer, so the waiting chain behind it grows even when each normal update is small.
Interactive Systems Explainers