Domain rotation for prelanders: pools and failover
By PLCloaker team · · 6 min read
Every prelander runs on a domain, and a domain can stop working at any time: a certificate expires, a DNS record is changed by mistake, or the domain is flagged by a browser safety list and visitors see a warning instead of your page. If all your traffic goes through one domain, any of these takes the whole campaign down. Domain rotation spreads the traffic across several domains so that one failure is not the end of the day.
What is a domain pool?
A domain pool is a group of domains that can all serve the same pages. Visitors enter through one entry link, and each visit is sent to one of the domains in the pool. To the visitor nothing changes; to you, a problem with one domain affects only part of the traffic, and only until that domain is taken out of rotation.
Keep separate pools for different categories of offers. If one vertical gets a domain flagged, the other categories keep running on domains that were never associated with it.
How should traffic be spread across a pool?
- Weights. Give new domains a small share first and increase it as they prove stable.
- Sticky routing. A visitor should stay on the same domain for the whole visit, usually keyed on the click ID, so a reload or a second page view does not jump to another domain.
- A minimum size. A pool of one is not a pool. Keep at least one standby domain ready.
What makes a domain unhealthy?
| Problem | What the visitor sees | What to check |
|---|---|---|
| Expired or wrong certificate | A browser security error | HTTPS responds with a valid certificate |
| DNS or hosting change | Nothing loads | The domain resolves and returns your page |
| Flagged as unsafe | A full-page warning | Safety lists such as Google Safe Browsing |
| Expired registration | A parking page or nothing | Renewal dates at the registrar |
Google’s Safe Browsing site status tool shows whether a site is currently listed as dangerous, and Safe Browsing protections are built into major browsers, which is why a flag has an immediate effect on traffic.
How does failover work?
- Each domain in the pool is checked on a schedule.
- A domain that fails is marked unhealthy and receives no new visits.
- Its share is spread over the remaining healthy domains.
- You are notified, fix the problem, and switch the domain back on, or retire it.
The pool should refuse to remove its last healthy domain. Better a warning in the dashboard than a campaign with nowhere to send its traffic.
When should a domain be retired?
A domain that was flagged for safety reasons keeps that history. Reusing it risks the next campaign, so blacklist it: take it out of every pool and stop checking it, so it cannot be added back by accident. Domains with ordinary technical problems, such as an expired certificate, can come back once they are fixed.
How PLCloaker handles it
In PLCloaker you connect your own domains, group them into pools per category of offer, and give each one a weight. Visits stick to one domain per click ID, domains are checked on a schedule, unhealthy ones are skipped, and burnt ones can be blacklisted so they never return. See domain pools on the features overview, and how to pass sub-IDs to your tracker for the tracking side of the same setup.
Written by the PLCloaker team
We build PLCloaker and run affiliate traffic with it every day. Questions or corrections: contact us.
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