[role="xpack"]
[testenv="basic"]
[[rollup-get-rollup-index-caps]]
=== Get rollup index capabilities API
++++
<titleabbrev>Get rollup index caps</titleabbrev>
++++

experimental[]

This API returns the rollup capabilities of all jobs inside of a rollup index (e.g. the index where rollup data is stored).
A single rollup index may store the data for multiple rollup jobs, and may have a variety of capabilities depending on those jobs.

This API will allow you to determine:

1. What jobs are stored in an index (or indices specified via a pattern)?
2. What target indices were rolled up, what fields were used in those rollups and what aggregations can be performed on each job?

==== Request

`GET {index}/_rollup/data`

//===== Description

==== Path Parameters

`index`::
  (string) Index or index-pattern of concrete rollup indices to check for capabilities.

==== Request Body

There is no request body for the Get Jobs API.

==== Authorization

You must have the `read` index privilege on the index that stores the rollup results.
For more information, see
{xpack-ref}/security-privileges.html[Security Privileges].

==== Examples

Imagine we have an index named `sensor-1` full of raw data.  We know that the data will grow over time, so there
will be a `sensor-2`, `sensor-3`, etc.  Let's create a Rollup job, which stores it's data in `sensor_rollup`:

[source,console]
--------------------------------------------------
PUT _rollup/job/sensor
{
    "index_pattern": "sensor-*",
    "rollup_index": "sensor_rollup",
    "cron": "*/30 * * * * ?",
    "page_size" :1000,
    "groups" : {
      "date_histogram": {
        "field": "timestamp",
        "fixed_interval": "1h",
        "delay": "7d"
      },
      "terms": {
        "fields": ["node"]
      }
    },
    "metrics": [
        {
            "field": "temperature",
            "metrics": ["min", "max", "sum"]
        },
        {
            "field": "voltage",
            "metrics": ["avg"]
        }
    ]
}
--------------------------------------------------
// TEST[setup:sensor_index]

If at a later date, we'd like to determine what jobs and capabilities were stored in the `sensor_rollup` index, we can use the Get Rollup
Index API:

[source,console]
--------------------------------------------------
GET /sensor_rollup/_rollup/data
--------------------------------------------------
// TEST[continued]

Note how we are requesting the concrete rollup index name (`sensor_rollup`) as the first part of the URL.
This  will yield the following response:

[source,console-result]
----
{
  "sensor_rollup" : {
    "rollup_jobs" : [
      {
        "job_id" : "sensor",
        "rollup_index" : "sensor_rollup",
        "index_pattern" : "sensor-*",
        "fields" : {
          "node" : [
            {
              "agg" : "terms"
            }
          ],
          "temperature" : [
            {
              "agg" : "min"
            },
            {
              "agg" : "max"
            },
            {
              "agg" : "sum"
            }
          ],
          "timestamp" : [
            {
              "agg" : "date_histogram",
              "time_zone" : "UTC",
              "fixed_interval" : "1h",
              "delay": "7d"
            }
          ],
          "voltage" : [
            {
              "agg" : "avg"
            }
          ]
        }
      }
    ]
  }
}
----


The response that is returned contains information that is similar to the original Rollup configuration, but formatted
differently.  First, there are some house-keeping details: the Rollup job's ID, the index that holds the rolled data,
the index pattern that the job was targeting.

Next it shows a list of fields that contain data eligible for rollup searches.  Here we see four fields: `node`, `temperature`,
`timestamp` and `voltage`.  Each of these fields list the aggregations that are possible.  For example, you can use a min, max
or sum aggregation on the `temperature` field, but only a `date_histogram` on `timestamp`.

Note that the `rollup_jobs` element is an array; there can be multiple, independent jobs configured for a single index
or index pattern.  Each of these jobs may have different configurations, so the API returns a list of all the various
configurations available.


Like other APIs that interact with indices, you can specify index patterns instead of explicit indices:

[source,console]
--------------------------------------------------
GET /*_rollup/_rollup/data
--------------------------------------------------
// TEST[continued]