(5) Job and instance instance | Prometheus (Prometheus)

In Prometheus terminology, an endpoint that you can scrape is called an instance , and usually corresponds to a single process. A collection of instances with the same purpose, such as a process replicated for scalability or reliability, is called a job .

For example, an API server job with four replication instances:

• job (job):api-server
  • Example 1:1.2.3.4:5670
  • Example 2:1.2.3.4:5671
  • Example 3:5.6.7.8:5670
  • Example 4:5.6.7.8:5671

Automatically generated labels and time series

When Prometheus grabs a target, it will automatically attach some tags to the captured time series to identify the captured target:

• job: The configured job name to which the target belongs.
• instance: <host>:<port>Part of the target URL to be crawled.

If any of these tags are already present in the scraped data, the behavior depends on honor_labelsconfiguration options. See  the crawl configuration documentation for more information  .

For each scrape instance, Prometheus stores samples in the following time series:

• up{job="<job-name>", instance="<instance-id>"}: 1If the instance is healthy, reachable, or 0if the fetch failed.
• scrape_duration_seconds{job="<job-name>", instance="<instance-id>"}: The duration of the crawl.
• scrape_samples_post_metric_relabeling{job="<job-name>", instance="<instance-id>"}: Number of samples remaining after applying metric relabeling.
• scrape_samples_scraped{job="<job-name>", instance="<instance-id>"}: Number of samples for target exposure.
• scrape_series_added{job="<job-name>", instance="<instance-id>"}: Approximate number of new series in this crawl. New features in v2.10

upTime series are useful for instance availability monitoring.