Detecting trends with aggregations
As we continue up the stack, let’s now examine some server performance metrics. How about an obvious web server metric? Enter prometheus_http_requests_total to get an idea of how many requests have been served so far:
Figure 4.15 – Prometheus HTTP requests
Well, this is a bit of a mess. You can’t see all 22 of the time series—they’re all stacked on top of each other—and there’s the ominous warning Selected metric is a counter. As we saw in the previous section, it’s no problem to apply filters—say, to filter the 200 codes—but then we’d still have a stack of nearly 20 individual series.
Applying aggregations to our query data
If only there were some way to combine all the individual data series into one. It turns out there is, and it’s called an aggregation. We can tell Prometheus to apply an aggregation function (in this case, sum...
