Search rolled-up data

The rollup search endpoint is needed because, internally, rolled-up documents utilize a different document structure than the original data. It rewrites standard Query DSL into a format that matches the rollup documents then takes the response and rewrites it back to what a client would expect given the original query.

The request body supports a subset of features from the regular search API. The following functionality is not available:

size: Because rollups work on pre-aggregated data, no search hits can be returned and so size must be set to zero or omitted entirely. highlighter, suggestors, post_filter, profile, explain: These are similarly disallowed.

Searching both historical rollup and non-rollup data

The rollup search API has the capability to search across both "live" non-rollup data and the aggregated rollup data. This is done by simply adding the live indices to the URI. For example:

GET sensor-1,sensor_rollup/_rollup_search
{
  "size": 0,
  "aggregations": {
     "max_temperature": {
      "max": {
        "field": "temperature"
      }
    }
  }
}
		

The rollup search endpoint does two things when the search runs:

• The original request is sent to the non-rollup index unaltered.
• A rewritten version of the original request is sent to the rollup index.

When the two responses are received, the endpoint rewrites the rollup response and merges the two together. During the merging process, if there is any overlap in buckets between the two responses, the buckets from the non-rollup index are used.