Server Log Ingestion
Also known as: log file analysis
Reading the web server's own request log so every hit is visible, including ones analytics never sees.
Server log ingestion pulls the raw record of requests the server actually handled. Unlike JavaScript analytics, it captures every request: bots, crawlers, non-rendering clients, and errors.
This depends entirely on hosting. Some platforms do not expose request logs to the site owner at all. Where that is the case, the rest of the data layer still works and this particular source simply is not available.