feat: deprecate DYN_SYSTEM_ENABLED in favor of DYN_SYSTEM_PORT (#4082)

Signed-off-by: Keiven Chang <keivenchang@users.noreply.github.com>
Co-authored-by: Keiven Chang <keivenchang@users.noreply.github.com>

components/src/dynamo/frontend/main.py

@@ -251,6 +251,16 @@ async def async_main():
     dump_config(flags.dump_config_to, flags)
     is_static = bool(flags.static_endpoint)  # true if the string has a value
 
+    # Warn if DYN_SYSTEM_PORT is set (frontend doesn't use system metrics server)
+    if os.environ.get("DYN_SYSTEM_PORT"):
+        logger.warning(
+            "=" * 80 + "\n"
+            "WARNING: DYN_SYSTEM_PORT is set but NOT used by the frontend!\n"
+            "The frontend does not expose a system metrics server.\n"
+            "Only backend workers should set DYN_SYSTEM_PORT.\n"
+            "Use --http-port to configure the frontend HTTP API port.\n" + "=" * 80
+        )
+
     # Configure Dynamo frontend HTTP service metrics prefix
     if flags.metrics_prefix is not None:
         prefix = flags.metrics_prefix.strip()

container/README.md

@@ -357,13 +357,13 @@ python -m dynamo.frontend &
 
 # 4. Start worker backend (choose one framework):
 # vLLM
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 python -m dynamo.vllm --model Qwen/Qwen3-0.6B --gpu-memory-utilization 0.20 --enforce-eager --no-enable-prefix-caching --max-num-seqs 64 &
+DYN_SYSTEM_PORT=8081 python -m dynamo.vllm --model Qwen/Qwen3-0.6B --gpu-memory-utilization 0.20 --enforce-eager --no-enable-prefix-caching --max-num-seqs 64 &
 
 # SGLang
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 python -m dynamo.sglang --model Qwen/Qwen3-0.6B --mem-fraction-static 0.20 --max-running-requests 64 &
+DYN_SYSTEM_PORT=8081 python -m dynamo.sglang --model Qwen/Qwen3-0.6B --mem-fraction-static 0.20 --max-running-requests 64 &
 
 # TensorRT-LLM
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 python -m dynamo.trtllm --model Qwen/Qwen3-0.6B --free-gpu-memory-fraction 0.20 --max-num-tokens 8192 --max-batch-size 64 &
+DYN_SYSTEM_PORT=8081 python -m dynamo.trtllm --model Qwen/Qwen3-0.6B --free-gpu-memory-fraction 0.20 --max-num-tokens 8192 --max-batch-size 64 &
 ```
 
 **Framework-Specific GPU Memory Arguments:**

deploy/cloud/operator/docs/footer.md

@@ -135,9 +135,8 @@ The operator automatically injects environment variables based on component type
 
 ### Worker Components
 
-- **`DYN_SYSTEM_ENABLED`**: `true`
+- **`DYN_SYSTEM_PORT`**: `9090` (automatically enables the system metrics server)
 - **`DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS`**: `["generate"]`
-- **`DYN_SYSTEM_PORT`**: `9090`
 
 ### Planner Components
 

deploy/cloud/operator/internal/controller/dynamocomponentdeployment_controller_test.go

@@ -827,7 +827,6 @@ func TestDynamoComponentDeploymentReconciler_generateLeaderWorkerSet(t *testing.
 											{Name: "DYN_NAMESPACE", Value: "default"},
 											{Name: "DYN_PARENT_DGD_K8S_NAME", Value: "test-lws-deploy"},
 											{Name: "DYN_PARENT_DGD_K8S_NAMESPACE", Value: "default"},
-											{Name: "DYN_SYSTEM_ENABLED", Value: "true"},
 											{Name: "DYN_SYSTEM_PORT", Value: "9090"},
 											{Name: "DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS", Value: "[\"generate\"]"},
 											{Name: "TEST_ENV_FROM_DYNAMO_COMPONENT_DEPLOYMENT_SPEC", Value: "test_value_from_dynamo_component_deployment_spec"},
@@ -941,7 +940,6 @@ func TestDynamoComponentDeploymentReconciler_generateLeaderWorkerSet(t *testing.
 											{Name: "DYN_NAMESPACE", Value: "default"},
 											{Name: "DYN_PARENT_DGD_K8S_NAME", Value: "test-lws-deploy"},
 											{Name: "DYN_PARENT_DGD_K8S_NAMESPACE", Value: "default"},
-											{Name: "DYN_SYSTEM_ENABLED", Value: "true"},
 											{Name: "DYN_SYSTEM_PORT", Value: "9090"},
 											{Name: "DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS", Value: "[\"generate\"]"},
 											{Name: "TEST_ENV_FROM_DYNAMO_COMPONENT_DEPLOYMENT_SPEC", Value: "test_value_from_dynamo_component_deployment_spec"},

deploy/cloud/operator/internal/dynamo/component_worker.go

@@ -74,10 +74,6 @@ func (w *WorkerDefaults) GetBaseContainer(context ComponentContext) (corev1.Cont
 	}
 
 	container.Env = append(container.Env, []corev1.EnvVar{
-		{
-			Name:  "DYN_SYSTEM_ENABLED",
-			Value: "true",
-		},
 		{
 			Name:  "DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS",
 			Value: "[\"generate\"]",

deploy/cloud/operator/internal/dynamo/graph_test.go

@@ -1818,10 +1818,6 @@ func TestGenerateGrovePodCliqueSet(t *testing.T) {
 														Name:  "DYNAMO_POD_GANG_SET_REPLICAS",
 														Value: "1",
 													},
-													{
-														Name:  "DYN_SYSTEM_ENABLED",
-														Value: "true",
-													},
 													{
 														Name:  "DYN_SYSTEM_PORT",
 														Value: "9090",
@@ -1971,10 +1967,6 @@ func TestGenerateGrovePodCliqueSet(t *testing.T) {
 														Name:  "DYNAMO_POD_GANG_SET_REPLICAS",
 														Value: "1",
 													},
-													{
-														Name:  "DYN_SYSTEM_ENABLED",
-														Value: "true",
-													},
 													{
 														Name:  "DYN_SYSTEM_PORT",
 														Value: "9090",
@@ -2623,10 +2615,6 @@ func TestGenerateGrovePodCliqueSet(t *testing.T) {
 														Name:  "DYNAMO_POD_GANG_SET_REPLICAS",
 														Value: "1",
 													},
-													{
-														Name:  "DYN_SYSTEM_ENABLED",
-														Value: "true",
-													},
 													{
 														Name:  "DYN_SYSTEM_PORT",
 														Value: "9090",
@@ -2763,10 +2751,6 @@ func TestGenerateGrovePodCliqueSet(t *testing.T) {
 														Name:  "DYNAMO_POD_GANG_SET_REPLICAS",
 														Value: "1",
 													},
-													{
-														Name:  "DYN_SYSTEM_ENABLED",
-														Value: "true",
-													},
 													{
 														Name:  "DYN_SYSTEM_PORT",
 														Value: "9090",
@@ -4595,7 +4579,6 @@ func TestGenerateBasePodSpec_Worker(t *testing.T) {
 							{Name: "DYN_NAMESPACE", Value: ""},
 							{Name: "DYN_PARENT_DGD_K8S_NAME", Value: "test-deployment"},
 							{Name: "DYN_PARENT_DGD_K8S_NAMESPACE", Value: "default"},
-							{Name: "DYN_SYSTEM_ENABLED", Value: "true"},
 							{Name: "DYN_SYSTEM_PORT", Value: "9090"},
 							{Name: "DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS", Value: "[\"generate\"]"},
 						},

deploy/helm/chart/templates/deployment.yaml

@@ -113,8 +113,6 @@ spec:
         - name: DYN_HTTP_PORT
           value: "{{ $.Values.dynamoPort | default 8000 }}"
         {{- else if $serviceSpec.componentType | eq "worker" }}
-        - name: DYN_SYSTEM_ENABLED
-          value: "true"
         - name: DYN_SYSTEM_PORT
           value: "{{ $.Values.dynamoSystemPort | default 9090 }}"
         - name: DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS

deploy/helm/chart/templates/grove-podgangset.yaml

@@ -105,8 +105,6 @@ spec:
             - name: DYN_HTTP_PORT
               value: "{{ $.Values.dynamoPort | default 8000 }}"
             {{- else if $serviceSpec.componentType | eq "worker" }}
-            - name: DYN_SYSTEM_ENABLED
-              value: "true"
             - name: DYN_SYSTEM_PORT
               value: "{{ $.Values.dynamoSystemPort | default 9090 }}"
             - name: DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS

deploy/metrics/prometheus.yml

@@ -41,7 +41,7 @@ scrape_configs:
     static_configs:
       - targets: ['host.docker.internal:8000']  # on the "monitoring" network
 
-  # Launch via: DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 dynamo.<backend> ...
+  # Launch via: DYN_SYSTEM_PORT=8081 dynamo.<backend> ...
   # If you want to update the scrape_interval, you may want to also update component.rs's MAX_DELAY
   - job_name: 'dynamo-backend'
     scrape_interval: 6s

docs/backends/sglang/prometheus.md

@@ -43,8 +43,7 @@ To see the actual metrics available in your SGLang version:
 ### 1. Launch SGLang with Metrics Enabled
 
 ```bash
-# Set environment variables
-export DYN_SYSTEM_ENABLED=true
+# Set system metrics port (automatically enables metrics server)
 export DYN_SYSTEM_PORT=8081
 
 # Start SGLang worker with metrics enabled

docs/backends/trtllm/prometheus.md

@@ -63,8 +63,7 @@ To see the actual metrics available in your TensorRT-LLM version:
 ### 1. Launch TensorRT-LLM with Metrics Enabled
 
 ```bash
-# Set environment variables
-export DYN_SYSTEM_ENABLED=true
+# Set system metrics port (automatically enables metrics server)
 export DYN_SYSTEM_PORT=8081
 
 # Start TensorRT-LLM worker with metrics enabled

docs/backends/vllm/prometheus.md

@@ -44,8 +44,7 @@ To see the actual metrics available in your vLLM version:
 ### 1. Launch vLLM with Metrics Enabled
 
 ```bash
-# Set environment variables
-export DYN_SYSTEM_ENABLED=true
+# Set system metrics port (automatically enables metrics server)
 export DYN_SYSTEM_PORT=8081
 
 # Start vLLM worker (metrics enabled by default via --disable-log-stats=false)

docs/kubernetes/api_reference.md

@@ -618,9 +618,8 @@ The operator automatically injects environment variables based on component type
 
 ### Worker Components
 
-- **`DYN_SYSTEM_ENABLED`**: `true`
+- **`DYN_SYSTEM_PORT`**: `9090` (automatically enables the system metrics server)
 - **`DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS`**: `["generate"]`
-- **`DYN_SYSTEM_PORT`**: `9090`
 
 ### Planner Components
 

docs/observability/health-checks.md

@@ -128,8 +128,7 @@ when initializing and HTTP status code `HTTP/1.1 200 OK` once ready.
 
 | **Environment Variable** | **Description**     | **Example Settings**                             |
 | -------------------------| ------------------- | ------------------------------------------------ |
-| `DYN_SYSTEM_ENABLED`     | Enables the system status server.                                            | `true`, `false`                           |
-| `DYN_SYSTEM_PORT`        | Specifies the port for the system status server.                              | `9090`                                   |
+| `DYN_SYSTEM_PORT`        | Specifies the port for the system status server (automatically enables it when set to a positive value). | `9090`, `8081`                           |
 | `DYN_SYSTEM_STARTING_HEALTH_STATUS`     | Sets the initial health status of the system (ready/not ready).                | `ready`, `notready`      |
 | `DYN_SYSTEM_HEALTH_PATH`                | Custom path for the health endpoint.                                         | `/custom/health`           |
 | `DYN_SYSTEM_LIVE_PATH`                   | Custom path for the liveness endpoint.                                       | `/custom/live`            |
@@ -138,10 +137,9 @@ when initializing and HTTP status code `HTTP/1.1 200 OK` once ready.
 ### Example Environment Setting
 
 ```
-export DYN_SYSTEM_ENABLED="true"
+export DYN_SYSTEM_PORT=9090
 export DYN_SYSTEM_STARTING_HEALTH_STATUS="notready"
 export DYN_SYSTEM_USE_ENDPOINT_HEALTH_STATUS="[\"generate\"]"
-export DYN_SYSTEM_PORT=9090
 ```
 
 #### Example Request

docs/observability/logging.md

@@ -214,7 +214,6 @@ The following shows the JSONL logs from the frontend service for the same reques
 
 ```
 {"time":"2025-10-31T20:52:07.707164Z","level":"INFO","file":"/opt/dynamo/lib/runtime/src/logging.rs","line":806,"target":"dynamo_runtime::logging","message":"OpenTelemetry OTLP export enabled","endpoint":"http://tempo.tm.svc.cluster.local:4317","service":"frontend"}
-...
 {"time":"2025-10-31T20:52:10.707164Z","level":"DEBUG","file":"/opt/dynamo/lib/runtime/src/pipeline/network/tcp/server.rs","line":230,"target":"dynamo_runtime::pipeline::network::tcp::server","message":"Registering new TcpStream on 10.0.4.65:41959","method":"POST","span_id":"5c20cc08e6afb2b7","span_name":"http-request","trace_id":"b672ccf48683b392891c5cb4163d4b51","uri":"/v1/chat/completions","version":"HTTP/1.1"}
 {"time":"2025-10-31T20:52:10.745264Z","level":"DEBUG","file":"/opt/dynamo/lib/llm/src/kv_router/prefill_router.rs","line":232,"target":"dynamo_llm::kv_router::prefill_router","message":"Prefill succeeded, using disaggregated params for decode","method":"POST","span_id":"5c20cc08e6afb2b7","span_name":"http-request","trace_id":"b672ccf48683b392891c5cb4163d4b51","uri":"/v1/chat/completions","version":"HTTP/1.1"}
 {"time":"2025-10-31T20:52:10.745545Z","level":"DEBUG","file":"/opt/dynamo/lib/runtime/src/pipeline/network/tcp/server.rs","line":230,"target":"dynamo_runtime::pipeline::network::tcp::server","message":"Registering new TcpStream on 10.0.4.65:41959","method":"POST","span_id":"5c20cc08e6afb2b7","span_name":"http-request","trace_id":"b672ccf48683b392891c5cb4163d4b51","uri":"/v1/chat/completions","version":"HTTP/1.1"}

docs/observability/prometheus-grafana.md

@@ -446,7 +446,7 @@ counter.inc();
 - **Automatic registration**: Metrics created via endpoint's `metrics().create_*()` factory methods are automatically registered with the system
 - Automatic labeling with namespace, component, and endpoint information
 - Consistent metric naming with `dynamo_` prefix
-- Built-in HTTP metrics endpoint when enabled with `DYN_SYSTEM_ENABLED=true`
+- Built-in HTTP metrics endpoint when `DYN_SYSTEM_PORT` is set to a positive value
 - Hierarchical metric organization
 
 ### Advanced Features

examples/backends/trtllm/launch/agg_metrics.sh

@@ -23,7 +23,7 @@ python3 -m dynamo.frontend --http-port 8000 &
 DYNAMO_PID=$!
 
 # Run worker
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 \
+DYN_SYSTEM_PORT=8081 \
 python3 -m dynamo.trtllm \
   --model-path "$MODEL_PATH" \
   --served-model-name "$SERVED_MODEL_NAME" \

examples/backends/vllm/launch/agg.sh

@@ -9,5 +9,5 @@ python -m dynamo.frontend --http-port=8000 &
 
 # run worker
 # --enforce-eager is added for quick deployment. for production use, need to remove this flag
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 \
+DYN_SYSTEM_PORT=8081 \
     python -m dynamo.vllm --model Qwen/Qwen3-0.6B --enforce-eager --connector none

lib/bindings/python/examples/metrics/README.md

@@ -379,19 +379,18 @@ maturin develop
 
 ```bash
 cd ~/dynamo/lib/bindings/python/examples/metrics
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 ./server_with_loop.py
+DYN_SYSTEM_PORT=8081 ./server_with_loop.py
 ```
 
 #### Run Example B: Callback-based Updates
 
 ```bash
 cd ~/dynamo/lib/bindings/python/examples/metrics
-DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 ./server_with_callback.py
+DYN_SYSTEM_PORT=8081 ./server_with_callback.py
 ```
 
-**Note:** The environment variables are required:
-- `DYN_SYSTEM_ENABLED=true` - Enables the system status server
-- `DYN_SYSTEM_PORT=8081` - Sets the port for the metrics endpoint
+**Note:** The environment variable is required:
+- `DYN_SYSTEM_PORT=8081` - Sets the port for the metrics endpoint (automatically enables the system status server)
 
 #### Check the Metrics
 

lib/bindings/python/examples/metrics/server_with_callback.py

@@ -12,7 +12,7 @@ This shows how Python code can:
 4. The metrics are automatically served via the /metrics endpoint
 
 Usage:
-    DYN_SYSTEM_ENABLED=true DYN_SYSTEM_PORT=8081 ./server_with_callback.py
+    DYN_SYSTEM_PORT=8081 ./server_with_callback.py
 
     # In another terminal, query the metrics:
     curl http://localhost:8081/metrics