[Misc] Adding script to setup ray for multi-node vllm deployments (#12913)

examples/online_serving/multi-node-serving.sh

+#!/bin/bash
+
+subcommand=$1
+shift
+
+ray_port=6379
+ray_init_timeout=300
+declare -a start_params
+
+case "$subcommand" in
+  worker)
+    ray_address=""
+    while [ $# -gt 0 ]; do
+      case "$1" in
+        --ray_address=*)
+          ray_address="${1#*=}"
+          ;;
+        --ray_port=*)
+          ray_port="${1#*=}"
+          ;;
+        --ray_init_timeout=*)
+          ray_init_timeout="${1#*=}"
+          ;;
+        *)
+          start_params+=("$1")
+      esac
+      shift
+    done
+
+    if [ -z "$ray_address" ]; then
+      echo "Error: Missing argument --ray_address"
+      exit 1
+    fi
+
+    for (( i=0; i < $ray_init_timeout; i+=5 )); do
+      ray start --address=$ray_address:$ray_port --block "${start_params[@]}"
+      if [ $? -eq 0 ]; then
+        echo "Worker: Ray runtime started with head address $ray_address:$ray_port"
+        exit 0
+      fi
+      echo "Waiting until the ray worker is active..."
+      sleep 5s;
+    done
+    echo "Ray worker starts timeout, head address: $ray_address:$ray_port"
+    exit 1
+    ;;
+
+  leader)
+    ray_cluster_size=""
+    while [ $# -gt 0 ]; do
+          case "$1" in
+            --ray_port=*)
+              ray_port="${1#*=}"
+              ;;
+            --ray_cluster_size=*)
+              ray_cluster_size="${1#*=}"
+              ;;
+            --ray_init_timeout=*)
+              ray_init_timeout="${1#*=}"
+              ;;
+            *)
+              start_params+=("$1")
+          esac
+          shift
+    done
+
+    if [ -z "$ray_cluster_size" ]; then
+      echo "Error: Missing argument --ray_cluster_size"
+      exit 1
+    fi
+
+    # start the ray daemon
+    ray start --head --port=$ray_port "${start_params[@]}"
+
+    # wait until all workers are active
+    for (( i=0; i < $ray_init_timeout; i+=5 )); do
+        active_nodes=`python3 -c 'import ray; ray.init(); print(sum(node["Alive"] for node in ray.nodes()))'`
+        if [ $active_nodes -eq $ray_cluster_size ]; then
+          echo "All ray workers are active and the ray cluster is initialized successfully."
+          exit 0
+        fi
+        echo "Wait for all ray workers to be active. $active_nodes/$ray_cluster_size is active"
+        sleep 5s;
+    done
+
+    echo "Waiting for all ray workers to be active timed out."
+    exit 1
+    ;;
+
+  *)
+    echo "unknown subcommand: $subcommand"
+    exit 1
+    ;;
+esac