Added missing cancellation_time_millis. (opensearch-project#747)

Signed-off-by: dblock <[email protected]>

CHANGELOG.md

@@ -36,6 +36,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added support for using a certificate and key in tests ([#731](https://github.com/opensearch-project/opensearch-api-specification/pull/731))
 - Added `_type` to `termvector` and `mtermvector` ([#734](https://github.com/opensearch-project/opensearch-api-specification/pull/734))
 - Added missing `cancelled` and `resource_stats` to `/_reindex/{task_id}/_rethrottle` ([#740](https://github.com/opensearch-project/opensearch-api-specification/pull/740))
+- Added missing `cancellation_time_millis` to `POST /_tasks/_cancel` ([#747](https://github.com/opensearch-project/opensearch-api-specification/pull/747))
 
 ### Removed
 - Removed unsupported `_common.mapping:SourceField`'s `mode` field and associated `_common.mapping:SourceFieldMode` enum ([#652](https://github.com/opensearch-project/opensearch-api-specification/pull/652))

spec/schemas/tasks._common.yaml

@@ -44,6 +44,8 @@ components:
           type: boolean
         cancellable:
           type: boolean
+        cancellation_time_millis:
+          $ref: '_common.yaml#/components/schemas/EpochTimeUnitMillis'
         description:
           type: string
         headers:

tests/default/_core/tasks/cancel.yaml

@@ -1,7 +1,20 @@
 $schema: ../../../../json_schemas/test_story.schema.yaml
 
 description: Test tasks endpoint.
+epilogues:
+  - path: /books
+    method: DELETE
+    status: [200, 404]
 prologues:
+  - path: /_bulk
+    method: POST
+    parameters:
+      refresh: true
+    request:
+      content_type: application/x-ndjson
+      payload:
+        - {create: {_index: books}}
+        - {author: Harper Lee, title: To Kill a Mockingbird, year: 1960}
   - path: /books/_delete_by_query
     id: task
     method: POST
@@ -24,10 +37,3 @@ chapters:
     method: POST
     parameters:
       task_id: ${task.id}
-    response:
-      status: 200
-      payload:
-        node_failures:
-          - type: failed_node_exception
-            caused_by:
-              type: resource_not_found_exception