Importance
These become increasingly important for infrastructure design questions; e.g. rate limiting and caching.
Napkin Estimations
When performing “napkin estimations”, focus on the answer’s order of magnitude. The correct coefficient is not nearly as important as the correct exponent. See the Napkin Estimates guide for more pointers.
What to Measure
Read versus write
Note
RPSandQPSmay differ between read operations and write operations.
DAU(daily active users)RPS(requests per second (entry point server))QPS(queries per second (database))TPS(transactions per second) is a unit of measurement forQPS- Ongoing connections (web sockets)
- Throughput (capacity of a system to handle load)
- Latency
- Response time
- Storage size
See Numbers You Should Know for insights into common values for these metrics.