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THE FEUTEX TOOLKIT

DNS Cache Query Rate

Estimate authoritative misses for a continuously used name with a fixed TTL.

Networking workspace● Runs in your browser
01 Your input
02 Your result
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FormulaEstimated upstream query rate = clients/(ttl+1/rate); Estimated cache hit ratio = 100*(1-1/(1+rate*ttl))

Made for real tasks

  • Estimate authoritative misses for a continuously used name with a fixed TTL.
Explore step-by-step workflows →

Worked example

Inputs

Independent caches
10000 caches
Queries per cache per second
0.1 queries/s
TTL
300 s

Expected results

Estimated upstream query rate
32.25806452 queries/s
Estimated cache hit ratio
96.77419355 %

Load the example in the workspace to reproduce these results. Display rounding does not change the underlying calculation.

How to use this tool

  1. Enter independent caches, queries per cache per second, ttl in the displayed units.
  2. Calculate the scenario, then compare it with measurements before changing a system.

Try this example

{
  "clients": 10000,
  "rate": 0.1,
  "ttl": 300
}

Accuracy and scope

Poisson arrivals, one name, no prefetch and refresh on first request after expiry; negative caching excluded.

Is my data uploaded?

This tool runs locally in your browser. Input and output are not sent to a processing server. Copy or download your result before leaving the page.