fix: port forward to available ports when benchmarking (#2795)

Signed-off-by: Hannah Zhang <hannahz@nvidia.com>

benchmarks/benchmark.sh

@@ -55,21 +55,26 @@ OPTIONS:
     --verbose                     Enable verbose output
 
 EXAMPLES:
-    # Compare aggregated vs disaggregated Dynamo deployments
+    # Compare Dynamo deployments of a single backend
     $0 --namespace \$NAMESPACE \\
        --input agg=components/backends/vllm/deploy/agg.yaml \\
        --input disagg=components/backends/vllm/deploy/disagg.yaml
 
+    # Compare different backend types (vLLM vs TensorRT-LLM)
+    $0 --namespace \$NAMESPACE \\
+       --input vllm-agg=components/backends/vllm/deploy/agg.yaml \\
+       --input trtllm-agg=components/backends/trtllm/deploy/agg.yaml
+
     # Compare Dynamo deployment vs external endpoint
     $0 --namespace \$NAMESPACE \\
        --input dynamo=components/backends/vllm/deploy/disagg.yaml \\
        --input external=http://localhost:8000
 
-    # Compare three different configurations
+    # Compare multiple different configurations (vLLM, TensorRT-LLM, SGLang)
     $0 --namespace \$NAMESPACE \\
-       --input dynamo-agg=components/backends/vllm/deploy/agg.yaml \\
-       --input dynamo-disagg=components/backends/vllm/deploy/disagg.yaml \\
-       --input external-vllm=http://localhost:8000
+       --input vllm-agg=components/backends/vllm/deploy/agg.yaml \\
+       --input trtllm-disagg=components/backends/trtllm/deploy/disagg.yaml \\
+       --input existing-sglang=http://localhost:8000
 
     # Benchmark a single Dynamo deployment
     $0 --namespace \$NAMESPACE \\

deploy/utils/dynamo_deployment.py

@@ -17,6 +17,7 @@ import argparse
 import asyncio
 import os
 import re
+import socket
 import subprocess
 import sys
 import time
@@ -29,6 +30,24 @@ import kubernetes_asyncio as kubernetes
 import yaml
 from kubernetes_asyncio import client, config
 
+
+def find_available_port(start_port: int = 8000) -> int:
+    """Find the first available TCP port on 127.0.0.1 starting at start_port (inclusive), scanning up to start_port+99."""
+    for port in range(
+        start_port, start_port + 100
+    ):  # Try ports start_port..start_port+99
+        try:
+            with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+                s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                s.bind(("127.0.0.1", port))
+                return port
+        except OSError:
+            continue
+    raise RuntimeError(
+        f"No available ports found in range {start_port}-{start_port+99}"
+    )
+
+
 # Example chat completion request for testing deployments
 EXAMPLE_CHAT_REQUEST = {
     "model": "Qwen/Qwen3-0.6B",
@@ -119,14 +138,21 @@ class DynamoDeploymentClient:
         self.custom_api = client.CustomObjectsApi(self.k8s_client)
         self.core_api = client.CoreV1Api(self.k8s_client)
 
-    def port_forward_frontend(self, local_port: int = 8000, quiet: bool = False) -> str:
+    def port_forward_frontend(
+        self, local_port: Optional[int] = None, quiet: bool = False
+    ) -> str:
         """
         Port forward the frontend service to a local port.
 
         Args:
-            local_port: Local port to forward to (default: 8000)
+            local_port: Local port to forward to (if None, find first available port starting from 8000)
             quiet: If True, suppress kubectl port-forward output messages (default: False)
         """
+        if local_port is None:
+            local_port = find_available_port(8000)
+            if not quiet:
+                print(f"Using available local port: {local_port}")
+
         cmd = [
             "kubectl",
             "port-forward",