Start transform API
editStart transform API
editStarts one or more transforms.
Request
editPOST _transform/<transform_id>/_start
Prerequisites
editIf the Elasticsearch security features are enabled, you must have the following built-in roles and privileges:
-
manage_transform
-
source index:
view_index_metadata
For more information, see Security privileges and Built-in roles.
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
.
The transform deduces the mapping definitions from the source indices. For
scripted fields, it uses dynamic mappings. If a field in the
destination index is created by scripted_metric
or bucket_script
aggregations, the transform uses dynamic mappings unless a template exists or
the destination index already exists. Mapping definitions in the destination
index take precedence over dynamic mappings and templates.
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 }