A collector is a metrics collector and is embedded in the prometheus server.
The scrape_configs block of the prometheus.yml file controls what resources Prometheus monitors. The below example shows a single job, called prometheus, which scrapes the metrics (time series data) exposed by an exporter (below this is the internal Prometheus server exporter)
Example:
scrape_configs:
- job_name: prometheus
static_configs:
- targets: ['localhost:9090']
scheme: 'https'
where:
Relabeling permits:
Relabeling Configuration:
Extra labels:
Internal labels begin with two underscores and are removed after all relabeling steps are applied
| Label name | Description |
|---|---|
| __name__ | The scraped metric’s name |
| __address__ | host:port of the scrape target |
| __scheme__ | URI scheme of the scrape target |
| __metrics_path__ | Metrics endpoint of the scrape target |
| __param_<name> | is the value of the first URL parameter passed to the target |
| __scrape_interval__ | The target’s scrape interval (experimental) |
| __scrape_timeout__ | The target’s timeout (experimental) |
| __meta_ | Special labels set set by the Service Discovery mechanism |
| __tmp | Special prefix used to temporarily store label values before discarding them |
After relabeling, the instance label is set to the value of __address__ by default if it was not set during relabeling.
Don't delete the instance label on relabel_config or you get an error because the collector don't know where to connect:
msg="Creating target failed" err="instance 0 in group endpoints/com-datacadamia/com-datacadamia: no address"
If you want to drop it, drop it on metric_relabel_configs