Operator tooling guide
Specific tooling recommendations for solo operators running a small internet business, with the trade-offs stated rather than hidden.
Calculators for people who run their own infrastructure, built from measurements taken on a production host rather than from vendor pricing pages.
The tools
- CDN bandwidth cost calculator — compares monthly egress cost across providers, including the per-request charge most comparisons leave out. For a site serving many small files that charge can exceed the bandwidth bill entirely.
- Container memory headroom calculator — works out whether a Docker host will run out of memory, and which container gets killed first, using observed working sets rather than configured limits. The defaults come from a host that was OOM-killed every two minutes.
- Reverse proxy restart blast radius calculator — turns a proxy's crash rate into the availability ceiling it imposes on every site behind it. Built from an outage where a proxy restarted every few minutes for days: each restart lasted about a second, which was too short to trip a 30-second health check and looked like flaky clients. Three backend replicas made no difference, because the ten sites shared one process.
- Sitemap generator and submission helper — builds a valid
sitemap.xmlfrom a list of URLs, generates an IndexNow key, and produces the exact commands to submit to IndexNow and to the Search Console API. It also names the routes that no longer work: Google deprecated its sitemap ping endpoint in June 2023 and it has returned 404 ever since, yet most tools in this category still advertise it.
Why these exist
Every calculator in these categories runs the same arithmetic from the same public documentation. That arithmetic is usually right and usually not the problem.
The problem is what the documentation does not say. A Docker memory limit is a ceiling rather than a reservation, so summing limits tells you very little about whether a host survives. A container is killed at a resident size well below its nominal limit, because cgroup accounting includes page cache. Raising that limit on a leaking process removes the protection the limit was providing. None of that appears in a configuration reference, and all of it is knowable only by running something and watching it fail.
Where a page cites a number, it says where the number came from. Where a figure is a vendor list price rather than a measurement, it says that too.
What these tools will not do
They do not phone home, store anything, or require an account. Every calculation runs in your browser, which is also why none of them can submit anything to a search engine on your behalf — that requires a server and a key you control.
Nothing here is a substitute for reading your own bill or your own dmesg. They are for the arithmetic in between.
Who writes this
One operator, running a handful of containers on a single oversubscribed box, publishing the calculations after getting them wrong first. Every page names the person who reviewed it and the date.