Start transform API
editStart transform API
editStarts one or more transforms.
Request
editPOST _transform/<transform_id>/_start
Prerequisites
editRequires the following privileges:
-
cluster:
manage_transform(thetransform_adminbuilt-in role grants this privilege) -
source indices:
read,view_index_metadata.
Description
editWhen you start a transform, it creates the destination index if it does not
already exist. The number_of_shards is set to 1 and the
auto_expand_replicas is set to 0-1.
If it is a pivot transform, it deduces the mapping definitions for the
destination index from the source indices and the transform aggregations. If
fields in the destination index are derived from scripts (as in the case of
scripted_metric or bucket_script aggregations), the transform uses
dynamic mappings unless an index template exists.
If it is a latest transform, it does not deduce mapping definitions; it uses dynamic mappings.
To use explicit mappings, create the destination index before you start the transform. Alternatively, you can create an index template, though it does not affect the deduced mappings in a pivot transform.
When the transform starts, a series of validations occur to ensure its success. If you deferred validation when you created the transform, they occur when you start the transform—with the exception of privilege checks. When Elasticsearch security features are enabled, the transform remembers which roles the user that created it had at the time of creation and uses those same roles. If those roles do not have the required privileges on the source and destination indices, the transform fails when it attempts unauthorized operations.
Path parameters
edit-
<transform_id> - (Required, string) Identifier for the transform. This identifier can contain lowercase alphanumeric characters (a-z and 0-9), hyphens, and underscores. It must start and end with alphanumeric characters.
Examples
editPOST _transform/ecommerce_transform/_start
When the transform starts, you receive the following results:
{
"acknowledged" : true
}