Add metric for async request payload size

common/metrics/defs.go

@@ -2178,6 +2178,8 @@ const (
 
 	HashringViewIdentifier
 
+	AsyncRequestPayloadSize
+
 	NumCommonMetrics // Needs to be last on this list for iota numbering
 )
 
@@ -2817,6 +2819,8 @@ var MetricDefs = map[ServiceIdx]map[int]metricDefinition{
 		IsolationGroupStateHealthy:           {metricName: "isolation_group_healthy", metricType: Counter},
 		ValidatedWorkflowCount:               {metricName: "task_validator_count", metricType: Counter},
 		HashringViewIdentifier:               {metricName: "hashring_view_identifier", metricType: Counter},
+
+		AsyncRequestPayloadSize: {metricName: "async_request_payload_size_per_domain", metricRollupName: "async_request_payload_size", metricType: Timer},
 	},
 	History: {
 		TaskRequests:             {metricName: "task_requests", metricType: Counter},

service/frontend/api/handler.go

@@ -1771,6 +1771,7 @@ func (wh *WorkflowHandler) StartWorkflowExecutionAsync(
 	if err != nil {
 		return nil, fmt.Errorf("failed to encode StartWorkflowExecutionAsyncRequest: %v", err)
 	}
+	scope.RecordTimer(metrics.AsyncRequestPayloadSize, time.Duration(len(payload)))
 
 	// propagate the headers from the context to the message
 	header := &shared.Header{
@@ -2351,6 +2352,7 @@ func (wh *WorkflowHandler) SignalWithStartWorkflowExecutionAsync(
 	if err != nil {
 		return nil, fmt.Errorf("failed to encode SignalWithStartWorkflowExecutionAsyncRequest: %v", err)
 	}
+	scope.RecordTimer(metrics.AsyncRequestPayloadSize, time.Duration(len(payload)))
 
 	// propagate the headers from the context to the message
 	header := &shared.Header{