> For the complete documentation index, see [llms.txt](https://docs.apica.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apica.io/observe/prometheus/querying-data.md).

# Writing queries

The Apica Ascent infra and application monitoring stack is compatible with Prometheus, Thanos, and Victoria Metrics and allows metrics to be pushed via the prometheus remote write protocol. This also allows user to query the metrics using standard PromQL style expressions. Using the query editor, type the PromQL query and see your data and create visualizations in an instant.

<figure><img src="/files/xa7hucVggepGZrEEMujX" alt=""><figcaption></figcaption></figure>

{% hint style="info" %}
Head over to the [Time Series Insights](/autonomous-insights/time-series-ai-ml.md) section to learn how to apply various anomaly and forecasting capabilities.
{% endhint %}

### Query language

The query language is nothing but the PromQL expression and any additional parameters that would be sent to the Prometheus Query API. The query starts with a `query=` prefix and ends with optional URL parameters that are sent to the query API

Let's look at an example

```
query=go_gc_duration_seconds&duration=15m&step=60
```

In the above query, we are looking for the `go_gc_duration_seconds` metric, sampled at 60-second intervals and duration for which data is needed which is the last 15 minutes.

The Prometheus Query API expects `start_time` and `end_time` to be provided in queries. Apica Ascent has a simplified `duration` syntax that is compatible with the Prometheus Query API.

Apica Ascent translates the duration values to appropriate start and end times before issuing the Query API call

{% hint style="info" %Apica Ascent} Using the duration syntax allows you to construct dynamic time range queries without specifying start or end time.

```
example: instant query
  query=http_requests_total

example: range query
  query=http_requests_total&start=2018-01-20T00:00:00.000Z&end=2018-01-25T00:00:00.000Z&step=60s

example: until now range query
  query=http_requests_total&start=2018-01-20T00:00:00.000Z&step=60s
  query=http_requests_total&start=2018-01-20T00:00:00.000Z&end=now&step=60s
  
example: using duration
  # end is assumed now, start is end-duration
  query=http_requests_total&duration=1h5m10s20ms&step=60s 
  # end is (start + duration)
  query=http_requests_total&start=2018-01-20T00:00:00.000Z&duration=1h&step=60s 
  # start is (end - duration), end is now
  query=http_requests_total&duration=1h&step=60s
  #start is (end - duration), end is now
  query=http_requests_total&end=2018-01-20T00:00:00.000Z&duration=1h&step=60s 
```

### PromQL compatibility

Apica Ascent's query language is 100% compatible with PromQL, primarily because all query expressions are translated to appropriate Prometheus Query / Query range API calls.

Let's look at a more complicated expression below

```
query=(100-(avg(irate(node_cpu_seconds_total{mode="idle"}[5m])) * 100))&duration=1h&step=30s
```

In the above example we are using several prometheus constructs

* Label based filtering e.g. `mode="idle"`
* Function such as `irate`, `avg`
* Using the vector syntax `[5m]`
* Mathematical operator like `* /` `-`


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.apica.io/observe/prometheus/querying-data.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.