Prometheus Service uses an intelligent detector to identify abnormal fluctuations
of KPI time-series data. This helps you make informative decisions in automatic data
loss protection and root cause analysis if alerts occur. This topic describes how
to use an intelligent detector to identify abnormal data fluctuations of a Prometheus
instance on a Grafana dashboard.
Detect abnormal data fluctuations of a Prometheus instance
- Log on to the ARMS console.
- In the left-side navigation pane, choose .
- In the upper-left corner of the page, select the region where the Prometheus instance
resides and click the dashboard of the Prometheus instance.
- In the left-side navigation pane, click the Explore icon. In the upper-left corner of the page, select a data source from the Explore drop-down list.
- Select a metric from the Metrics drop-down list to view the time-series data of the metric. For example, you can select
the following metric whose data anomalies you want to view:
arms_cms_collector_duration_seconds

- In the text box on the right of the Metrics drop-down list, enter the following PromQL statement. The statement is used as a
sample anomaly detector. This way, the abnormal data fluctuations about the metric
over a specific period of time can be identified.
anomal_detect (arms_cms_collector_duration_seconds[180m],3)
Note
- arms_cms_collector_duration_seconds: the name of the metric used in the previous step. You can replace it based on your business scenario.
- The data type of the metric that the PromQL statement queries must be range vector.
Therefore, you must append a time selector to the right of the metric name. The default
value of the time selector is [180m]. The default value of the parameter is 3. If
you execute other aggregate functions in advance, you must modify the time selector
to [180m:] in the PromQL statement. This way, you can change the data type of the
metric to range vector. For example, you can modify the PromQL statement to anonym_detect
(sum(node_memory_free_bytes)[180m:],3).
