Add poller autoscaling namespace capability (#723)

Author: Sushisource

openapi/openapiv2.json

@@ -13736,6 +13736,10 @@
         "workerPollCompleteOnShutdown": {
           "type": "boolean",
           "description": "True if the namespace supports server-side completion of outstanding worker polls on shutdown.\nWhen enabled, the server will complete polls for workers that send WorkerInstanceKey in their\npoll requests and call ShutdownWorker with the same WorkerInstanceKey. The poll will return\nan empty response. When this flag is true, workers should allow polls to return gracefully\nrather than terminating any open polls on shutdown."
+        },
+        "pollerAutoscaling": {
+          "type": "boolean",
+          "title": "True if the namespace supports poller autoscaling"
         }
       },
       "description": "Namespace capability details. Should contain what features are enabled in a namespace."

openapi/openapiv3.yaml

@@ -10767,6 +10767,9 @@ components:
              poll requests and call ShutdownWorker with the same WorkerInstanceKey. The poll will return
              an empty response. When this flag is true, workers should allow polls to return gracefully
              rather than terminating any open polls on shutdown.
+        pollerAutoscaling:
+          type: boolean
+          description: True if the namespace supports poller autoscaling
       description: Namespace capability details. Should contain what features are enabled in a namespace.
     NamespaceInfo_Limits:
       type: object

temporal/api/namespace/v1/message.proto

@@ -48,6 +48,8 @@ message NamespaceInfo {
         // an empty response. When this flag is true, workers should allow polls to return gracefully
         // rather than terminating any open polls on shutdown.
         bool worker_poll_complete_on_shutdown = 8;
+        // True if the namespace supports poller autoscaling
+        bool poller_autoscaling = 9;
     }
 
     // Namespace configured limits