Where do I submit the native tasks?

On Druid 0.12.1 I am trying to submit a “index_parallel” spec as described at http://druid.io/docs/latest/ingestion/native_tasks.html. I am trying to submit it to overlord using the API described at http://druid.io/docs/latest/operations/api-reference.html#overlord i.e. POST to the end point /druid/indexer/v1/task.

But I am getting error {

"error": "Could not resolve type id 'index_parallel' into a subtype of [simple type, class io.druid.indexing.common.task.Task]\n at [Source: HttpInputOverHTTP@5d1b80f0[c=5334,q=1,[0]=EOF,s=STREAM]; line: 1, column: 2]"

}

Which API end point should I be using to submit this task to overlord?

Sorry the druid version being used is 0.12.3 not 0.12.1

Went through the release notes and found that index_parallel was introduced in 0.13.0. That is the reason this was not working for me.