Siren Platform User Guide

Search APIs

Siren Federate introduces two new search actions, /siren/[INDICES]/_search that replaces the /[INDICES]/_search Elasticsearch’s action, and /siren/[INDICES]/_msearch that replaces the /[INDICES]/_msearch Elasticsearch’s action. Both actions are extensions of the original Elasticsearch’s actions and therefore supports the same API. One must use these actions with the join query clause, as the join query clause is not supported by the original Elasticsearch actions.

Search API

The search API allows you to execute a search query and get back search hits that match the query. The endpoint for it is /siren/[INDICES]/_search.

Multi search API

The multi search API allows you to execute several search requests within the same API. The endpoint for it is /siren/[INDICES]/_msearch.

Search request

The syntax for the body of the search request is identical to the one supported by Elasticsearch’s search API, with the additional support for the join query clause in the Query DSL.

Parameters

In addition to the parameters supported by Elasticsearch’s search API, Federate’s search API introduces the following additional parameters:

task_timeout

A task timeout, bounding a task to be executed within the specified time value (in milliseconds) and returns with the values accumulated up to that point when expired. Defaults to no timeout (-1).

debug

To retrieve debug information from the query planner. Defaults to false.

Search response

The response returned by Federate’s search API is similar to the response returned by Elasticsearch’s search API. It extends the response with a planner object which includes information about the query plan execution. If the task_timeout was activated, it will include the flag is_pruned to indicate that the search results are pruned and probably incomplete. If the debug parameter was enabled, it will also include the information and statistics about the query plan execution.

Cancelling a Request

A search or a multi search request can be canceled explicitly by a user through HTTP headers. In order to do so, you need to pass an X-Opaque-Id header which is used to identify the request. The endpoint for canceling a request is /_siren/job/<ID>/_cancel.

Usage

Let’s identity a search request with the ID my-request:

$ curl -H "Content-Type: application/json" -H "X-Opaque-Id: my-request" 'http://localhost:9200/siren/_search'

Then to cancel it, issue a request as follows:

$ curl -XPOST -H "Content-Type: application/json" 'localhost:9200/_siren/job/my-request/_cancel'

If successful, the response will acknowledge the request and give a listing of the canceled tasks:

{
  "acknowledged" : true,
  "tasks" : [
    {
      "node" : "5ILUA44uSee-VxsBsNbsNA",
      "id" : 947,
      "type" : "transport",
      "action" : "indices:siren/plan",
      "description" : "federate query",
      "start_time_in_millis" : 1524815599457,
      "running_time_in_nanos" : 199131478,
      "cancellable" : true,
      "headers" : {
        "X-Opaque-Id" : "my-request"
      }
    }
  ]
}

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