[Feat.] Enable grafana to show metrics (#4718)

Co-authored-by: zhaochenyang20 <zhaochen20@outlook.com>

docs/references/production_metrics.md

@@ -2,7 +2,7 @@
 
 SGLang exposes the following metrics via Prometheus. The metrics are namespaced by `$name` (the model name).
 
-An example of the monitoring dashboard is available in [examples/monitoring/grafana.json](../examples/monitoring/grafana.json).
+An example of the monitoring dashboard is available in [examples/monitoring/grafana.json](../examples/monitoring/grafana/dashboards/json/sglang-dashboard.json).
 
 Here is an example of the metrics:
 
@@ -150,7 +150,7 @@ In a new Grafana setup, ensure that you have the `Prometheus` data source enable
 
 If not, click `Add data source` -> `Prometheus`, set Prometheus URL to `http://localhost:9090`, and click `Save & Test`.
 
-To import the Grafana dashboard, click `+` -> `Import` -> `Upload JSON file` -> `Upload` and select [grafana.json](../examples/monitoring/grafana.json).
+To import the Grafana dashboard, click `+` -> `Import` -> `Upload JSON file` -> `Upload` and select [grafana.json](../examples/monitoring/grafana/dashboards/json/sglang-dashboard.json).
 
 ### Troubleshooting
 

examples/monitoring/README.md

+# SGLang Monitoring Setup
+
+This directory contains a ready-to-use monitoring setup for SGLang using Prometheus and Grafana.
+
+## Prerequisites
+
+- Docker and Docker Compose installed
+- SGLang server running with metrics enabled
+
+## Usage
+
+1. Start your SGLang server with metrics enabled:
+
+```bash
+python -m sglang.launch_server --model-path meta-llama/Meta-Llama-3.1-8B-Instruct --port 30000 --enable-metrics
+```
+
+By default, the metrics server will run on `127.0.0.1:30000`.
+
+2. Start the monitoring stack:
+
+```bash
+cd examples/monitoring
+docker compose up
+```
+
+3. Access the monitoring interfaces:
+   - Grafana: [http://localhost:3000](http://localhost:3000)
+   - Prometheus: [http://localhost:9090](http://localhost:9090)
+
+Default Grafana login credentials:
+- Username: `admin`
+- Password: `admin`
+
+You'll be prompted to change the password on first login.
+
+4. The SGLang dashboard will be automatically available in the "SGLang Monitoring" folder.
+
+## Troubleshooting
+
+### Port Conflicts
+If you see errors like "port is already allocated":
+
+1. Check if you already have Prometheus or Grafana running:
+   ```bash
+   docker ps | grep -E 'prometheus|grafana'
+   ```
+
+2. Stop any conflicting containers:
+   ```bash
+   docker stop <container_id>
+   ```
+
+3. Ensure no other services are using ports 9090 and 3000:
+   ```bash
+   lsof -i :9090
+   lsof -i :3000
+   ```
+
+### Connection Issues
+If Grafana cannot connect to Prometheus:
+1. Check that both services are running
+2. Verify the datasource configuration in Grafana
+3. Check that your SGLang server is properly exposing metrics
+
+## Configuration
+
+- Prometheus configuration: `prometheus.yaml`
+- Docker Compose configuration: `docker-compose.yaml`
+- Grafana datasource: `grafana/datasources/datasource.yaml`
+- Grafana dashboard configuration: `grafana/dashboards/config/dashboard.yaml`
+- SGLang dashboard JSON: `grafana/dashboards/json/sglang-dashboard.json`
+
+## Customization
+
+You can customize the monitoring setup by modifying the configuration files as needed.

examples/monitoring/docker-compose.yaml

+version: '3'
 services:
   prometheus:
     image: prom/prometheus:latest
+    container_name: prometheus
     network_mode: host
-    ports:
-      - "9090:9090"
     volumes:
-      - ${PWD}/prometheus.yaml:/etc/prometheus/prometheus.yml
+      - ./prometheus.yaml:/etc/prometheus/prometheus.yml
+    command:
+      - '--config.file=/etc/prometheus/prometheus.yml'
+      - '--storage.tsdb.path=/prometheus'
 
   grafana:
     image: grafana/grafana:latest
+    container_name: grafana
     network_mode: host
+    volumes:
+      - ./grafana/datasources:/etc/grafana/provisioning/datasources
+      - ./grafana/dashboards/config:/etc/grafana/provisioning/dashboards
+      - ./grafana/dashboards/json:/var/lib/grafana/dashboards
+    environment:
+      - GF_AUTH_ANONYMOUS_ENABLED=true
+      - GF_AUTH_ANONYMOUS_ORG_ROLE=Viewer
+      - GF_AUTH_BASIC_ENABLED=false
+      - GF_USERS_ALLOW_SIGN_UP=false
+      - GF_DASHBOARDS_DEFAULT_HOME_DASHBOARD_PATH=/var/lib/grafana/dashboards/sglang-dashboard.json
     depends_on:
       - prometheus
-    ports:
-      - "3000:3000"

examples/monitoring/grafana/dashboards/config/dashboard.yaml

+apiVersion: 1
+providers:
+  - name: 'SGLang'
+    orgId: 1
+    folder: 'SGLang Monitoring'
+    type: file
+    disableDeletion: false
+    updateIntervalSeconds: 10
+    allowUiUpdates: false
+    options:
+      path: /var/lib/grafana/dashboards

examples/monitoring/grafana.json → examples/monitoring/grafana/dashboards/json/sglang-dashboard.json

@@ -388,7 +388,7 @@
           },
           "disableTextWrap": false,
           "editorMode": "code",
-          "expr": "histogram_quantile(0.95, sum by (le) (rate(sglang:time_to_first_token_seconds_bucket[$__rate_interval])))\r\n",
+          "expr": "histogram_quantile(0.5, sum by (le) (rate(sglang:time_to_first_token_seconds_bucket[$__rate_interval])))\r\n",
           "fullMetaSearch": false,
           "hide": false,
           "includeNullMetadata": true,

examples/monitoring/grafana/datasources/datasource.yaml

+apiVersion: 1
+datasources:
+  - name: Prometheus
+    type: prometheus
+    access: proxy
+    url: http://localhost:9090
+    isDefault: true
+    editable: false