Revert "Disable async serve handler in Ray Service cluster (#447)" (#606

)

This reverts commit de8e242.

Why are these changes needed?
Ray 2.0 lets users build their Serve deployment graphs using async handles. However, KubeRay disables async handles by default. Once users build their deployment graphs, they attempt to use it with KubeRay but must add code changes to remove double await statements used with async handles. See Issue #28908 in the Ray repo for more info.

This change removes the logic that disables async handles in KubeRay.

ray-operator/controllers/ray/common/constant.go

@@ -72,7 +72,6 @@ const (
 	RAY_TIMEOUT_MS_TASK_WAIT_FOR_DEATH_INFO = "RAY_timeout_ms_task_wait_for_death_info"
 	RAY_GCS_SERVER_REQUEST_TIMEOUT_SECONDS  = "RAY_gcs_server_request_timeout_seconds"
 	RAY_SERVE_KV_TIMEOUT_S                  = "RAY_SERVE_KV_TIMEOUT_S"
-	SERVE_DEPLOYMENT_HANDLE_IS_SYNC         = "SERVE_DEPLOYMENT_HANDLE_IS_SYNC"
 	SERVE_CONTROLLER_PIN_ON_NODE            = "RAY_INTERNAL_SERVE_CONTROLLER_PIN_ON_NODE"
 	RAY_USAGE_STATS_KUBERAY_IN_USE          = "RAY_USAGE_STATS_KUBERAY_IN_USE"
 

ray-operator/controllers/ray/common/pod.go

@@ -571,10 +571,6 @@ func setContainerEnvVars(pod *v1.Pod, rayContainerIndex int, rayNodeType rayiov1
 			gcsTimeoutEnv := v1.EnvVar{Name: RAY_GCS_SERVER_REQUEST_TIMEOUT_SECONDS, Value: "5"}
 			container.Env = append(container.Env, gcsTimeoutEnv)
 		}
-		if !envVarExists(SERVE_DEPLOYMENT_HANDLE_IS_SYNC, container.Env) {
-			serveHandleSync := v1.EnvVar{Name: SERVE_DEPLOYMENT_HANDLE_IS_SYNC, Value: "1"}
-			container.Env = append(container.Env, serveHandleSync)
-		}
 		if !envVarExists(RAY_SERVE_KV_TIMEOUT_S, container.Env) {
 			serveKvTimeoutEnv := v1.EnvVar{Name: RAY_SERVE_KV_TIMEOUT_S, Value: "5"}
 			container.Env = append(container.Env, serveKvTimeoutEnv)