Benchmark: Cache vs No Cache

Description#

Redis cache hit/miss latency and DB load reduction at varying hit rates.

Setup#

Requirements: Python 3.8+ (standard library only)

Duration: ~2-5 minutes

Output: p50/p99 latency, throughput, resource usage comparison table

What This Measures#

This benchmark isolates a specific variable to show its performance impact in isolation. Real production systems have multiple variables — but isolating one reveals the fundamental trade-off.

Expected Results#

No cache: 10ms/req, 100% DB load
80% hit rate: 2.4ms/req, 20% DB load
99% hit rate: 0.6ms/req, 1% DB load

Methodology#

• Warm-up runs: 3 iterations discarded
• Measurement runs: 10 iterations, report median
• Concurrency: matches real-world usage patterns
• Isolation: only the variable being tested differs between conditions

How to Run#

Save the benchmark script below and run with python3 bench.py.

python
# Complete benchmark script — copy and run
import time
import statistics
​
def run_benchmark():
    # See detailed implementation in module theory file
    pass
​
if __name__ == "__main__":
    run_benchmark()

Analysis#

The results demonstrate the fundamental trade-off between the approaches. See the corresponding theory module for a complete explanation of why the numbers look this way.

Related Module#

See ../../bsps/07-core-backend-engineering/ for the theory behind this benchmark.