TaskQueue per-priority stats (#611)

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<!-- Describe what has changed in this PR -->
**What changed?**

Adding a breakdown of stats per-priority levels to the two APIs that
return task queue stats already.

<!-- Tell your future self why have you made these changes -->
**Why?**

To give users insights on a per priority level.

<!-- Are there any breaking changes on binary or code level? -->
**Breaking changes**

N/A

<!-- If this breaks the Server, please provide the Server PR to merge
right after this PR was merged. -->
**Server PR**

temporalio/temporal#8030

Author: stephanos

openapi/openapiv2.json

@@ -7224,6 +7224,13 @@
         "stats": {
           "$ref": "#/definitions/v1TaskQueueStats",
           "description": "Only set if `report_task_queue_stats` is set on the request."
+        },
+        "statsByPriorityKey": {
+          "type": "object",
+          "additionalProperties": {
+            "$ref": "#/definitions/v1TaskQueueStats"
+          },
+          "description": "Task queue stats breakdown by priority key. Only contains actively used priority keys.\nOnly set if `report_task_queue_stats` is set to true in the request."
         }
       }
     },
@@ -10804,14 +10811,21 @@
             "$ref": "#/definitions/v1PollerInfo"
           }
         },
+        "stats": {
+          "$ref": "#/definitions/v1TaskQueueStats",
+          "description": "Statistics for the task queue.\nOnly set if `report_stats` is set on the request."
+        },
+        "statsByPriorityKey": {
+          "type": "object",
+          "additionalProperties": {
+            "$ref": "#/definitions/v1TaskQueueStats"
+          },
+          "description": "Task queue stats breakdown by priority key. Only contains actively used priority keys.\nOnly set if `report_stats` is set on the request."
+        },
         "versioningInfo": {
           "$ref": "#/definitions/v1TaskQueueVersioningInfo",
           "description": "Specifies which Worker Deployment Version(s) Server routes this Task Queue's tasks to.\nWhen not present, it means the tasks are routed to Unversioned workers (workers with\nUNVERSIONED or unspecified WorkerVersioningMode.)\nTask Queue Versioning info is updated indirectly by calling SetWorkerDeploymentCurrentVersion\nand SetWorkerDeploymentRampingVersion on Worker Deployments.\nNote: This information is not relevant to Pinned workflow executions and their activities as\nthey are always routed to their Pinned Deployment Version. However, new workflow executions\nare typically not Pinned until they complete their first task (unless they are started with\na Pinned VersioningOverride or are Child Workflows of a Pinned parent)."
         },
-        "stats": {
-          "$ref": "#/definitions/v1TaskQueueStats",
-          "description": "Statistics for the task queue. Only populated when `report_stats` is set to true in the request."
-        },
         "config": {
           "$ref": "#/definitions/v1TaskQueueConfig",
           "description": "Only populated if report_task_queue_config is set to true."

openapi/openapiv3.yaml

@@ -7805,6 +7805,21 @@ components:
           type: array
           items:
             $ref: '#/components/schemas/PollerInfo'
+        stats:
+          allOf:
+            - $ref: '#/components/schemas/TaskQueueStats'
+          description: |-
+            Statistics for the task queue.
+             Only set if `report_stats` is set on the request.
+        statsByPriorityKey:
+          type: object
+          additionalProperties:
+            $ref: '#/components/schemas/TaskQueueStats'
+          description: |-
+            Task queue stats breakdown by priority key. Only contains actively used priority keys.
+             Only set if `report_stats` is set on the request.
+             (-- api-linter: core::0140::prepositions=disabled
+                 aip.dev/not-precedent: "by" is used to clarify the keys and values. --)
         versioningInfo:
           allOf:
             - $ref: '#/components/schemas/TaskQueueVersioningInfo'
@@ -7818,10 +7833,6 @@ components:
              they are always routed to their Pinned Deployment Version. However, new workflow executions
              are typically not Pinned until they complete their first task (unless they are started with
              a Pinned VersioningOverride or are Child Workflows of a Pinned parent).
-        stats:
-          allOf:
-            - $ref: '#/components/schemas/TaskQueueStats'
-          description: Statistics for the task queue. Only populated when `report_stats` is set to true in the request.
         config:
           allOf:
             - $ref: '#/components/schemas/TaskQueueConfig'
@@ -7901,6 +7912,15 @@ components:
           allOf:
             - $ref: '#/components/schemas/TaskQueueStats'
           description: Only set if `report_task_queue_stats` is set on the request.
+        statsByPriorityKey:
+          type: object
+          additionalProperties:
+            $ref: '#/components/schemas/TaskQueueStats'
+          description: |-
+            Task queue stats breakdown by priority key. Only contains actively used priority keys.
+             Only set if `report_task_queue_stats` is set to true in the request.
+             (-- api-linter: core::0140::prepositions=disabled
+                 aip.dev/not-precedent: "by" is used to clarify the key. --)
     DescribeWorkflowExecutionResponse:
       type: object
       properties:

temporal/api/workflowservice/v1/request_response.proto

@@ -1095,6 +1095,16 @@ message DescribeTaskQueueRequest {
 message DescribeTaskQueueResponse {
     repeated temporal.api.taskqueue.v1.PollerInfo pollers = 1;
 
+    // Statistics for the task queue.
+    // Only set if `report_stats` is set on the request.
+    temporal.api.taskqueue.v1.TaskQueueStats stats = 5;
+
+    // Task queue stats breakdown by priority key. Only contains actively used priority keys.
+    // Only set if `report_stats` is set on the request.
+    // (-- api-linter: core::0140::prepositions=disabled
+    //     aip.dev/not-precedent: "by" is used to clarify the keys and values. --)
+    map<int32, temporal.api.taskqueue.v1.TaskQueueStats> stats_by_priority_key = 8;
+
     // Specifies which Worker Deployment Version(s) Server routes this Task Queue's tasks to.
     // When not present, it means the tasks are routed to Unversioned workers (workers with
     // UNVERSIONED or unspecified WorkerVersioningMode.)
@@ -1106,9 +1116,6 @@ message DescribeTaskQueueResponse {
     // a Pinned VersioningOverride or are Child Workflows of a Pinned parent).
     temporal.api.taskqueue.v1.TaskQueueVersioningInfo versioning_info = 4;
 
-    // Statistics for the task queue. Only populated when `report_stats` is set to true in the request.
-    temporal.api.taskqueue.v1.TaskQueueStats stats = 5;
-
     // Only populated if report_task_queue_config is set to true.
     temporal.api.taskqueue.v1.TaskQueueConfig config  = 6;
 
@@ -2069,6 +2076,11 @@ message DescribeWorkerDeploymentVersionResponse {
         temporal.api.enums.v1.TaskQueueType type = 2;
         // Only set if `report_task_queue_stats` is set on the request.
         temporal.api.taskqueue.v1.TaskQueueStats stats = 3;
+        // Task queue stats breakdown by priority key. Only contains actively used priority keys.
+        // Only set if `report_task_queue_stats` is set to true in the request.
+        // (-- api-linter: core::0140::prepositions=disabled
+        //     aip.dev/not-precedent: "by" is used to clarify the key. --)
+        map<int32, temporal.api.taskqueue.v1.TaskQueueStats> stats_by_priority_key = 4;
     }
 }