[Example] add one-click runnable example for P2P NCCL XpYd (#20246)

Signed-off-by: KuntaiDu <kuntai@uchicago.edu>

examples/online_serving/disaggregated_serving_p2p_nccl_xpyd/disagg_example_p2p_nccl_xpyd.sh

+#!/bin/bash
+
+# =============================================================================
+# vLLM Disaggregated Serving Script - P2P NCCL XpYd Architecture
+# =============================================================================
+# This script demonstrates disaggregated prefill and decode serving using
+# P2P NCCL communication. The architecture supports various XpYd configurations:
+#
+# - 1P3D: 1 Prefill server + 3 Decode servers (current default)
+# - 3P1D: 3 Prefill servers + 1 Decode server
+# - etc.
+#
+# Configuration can be customized via environment variables:
+#   MODEL: Model to serve
+#   PREFILL_GPUS: Comma-separated GPU IDs for prefill servers
+#   DECODE_GPUS: Comma-separated GPU IDs for decode servers
+#   PREFILL_PORTS: Comma-separated ports for prefill servers
+#   DECODE_PORTS: Comma-separated ports for decode servers
+#   PROXY_PORT: Proxy server port used to setup XpYd connection.
+#   TIMEOUT_SECONDS: Server startup timeout
+# =============================================================================
+
+# Configuration - can be overridden via environment variables
+MODEL=${MODEL:-meta-llama/Llama-3.1-8B-Instruct}
+TIMEOUT_SECONDS=${TIMEOUT_SECONDS:-1200}
+PROXY_PORT=${PROXY_PORT:-30001}
+
+# Default 1P3D configuration (1 Prefill + 3 Decode)
+PREFILL_GPUS=${PREFILL_GPUS:-0}
+DECODE_GPUS=${DECODE_GPUS:-1,2,3}
+PREFILL_PORTS=${PREFILL_PORTS:-20003}
+DECODE_PORTS=${DECODE_PORTS:-20005,20007,20009} 
+
+echo "Warning: P2P NCCL disaggregated prefill XpYd support for vLLM v1 is experimental and subject to change."
+echo ""
+echo "Architecture Configuration:"
+echo "  Model: $MODEL"
+echo "  Prefill GPUs: $PREFILL_GPUS, Ports: $PREFILL_PORTS"
+echo "  Decode GPUs: $DECODE_GPUS, Ports: $DECODE_PORTS"
+echo "  Proxy Port: $PROXY_PORT"
+echo "  Timeout: ${TIMEOUT_SECONDS}s"
+echo ""
+
+PIDS=()
+
+# Switch to the directory of the current script
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
+check_required_files() {
+    local files=("disagg_proxy_p2p_nccl_xpyd.py")
+    for file in "${files[@]}"; do
+        if [[ ! -f "$file" ]]; then
+            echo "Required file $file not found in $(pwd)"
+            exit 1
+        fi
+    done
+}
+
+check_hf_token() {
+    if [ -z "$HF_TOKEN" ]; then
+        echo "HF_TOKEN is not set. Please set it to your Hugging Face token."
+        echo "Example: export HF_TOKEN=your_token_here"
+        exit 1
+    fi
+    if [[ "$HF_TOKEN" != hf_* ]]; then
+        echo "HF_TOKEN is not a valid Hugging Face token. Please set it to your Hugging Face token."
+        exit 1
+    fi
+    echo "HF_TOKEN is set and valid."
+}
+
+check_num_gpus() {
+    # Check if the number of GPUs are >=2 via nvidia-smi
+    num_gpus=$(nvidia-smi --query-gpu=name --format=csv,noheader | wc -l)
+    if [ "$num_gpus" -lt 2 ]; then
+        echo "You need at least 2 GPUs to run disaggregated prefill."
+        exit 1
+    else
+        echo "Found $num_gpus GPUs."
+    fi
+}
+
+ensure_python_library_installed() {
+    echo "Checking if $1 is installed..."
+    if ! python3 -c "import $1" > /dev/null 2>&1; then
+        echo "$1 is not installed. Please install it via pip install $1."
+        exit 1
+    else
+        echo "$1 is installed."
+    fi
+}
+
+cleanup() {
+    echo "Stopping everything…"
+    trap - INT TERM        # prevent re-entrancy
+    kill -- -$$            # negative PID  ==  "this whole process-group"
+    wait                   # reap children so we don't leave zombies
+    exit 0
+}
+
+wait_for_server() {
+  local port=$1
+  local timeout_seconds=$TIMEOUT_SECONDS
+  local start_time=$(date +%s)
+
+  echo "Waiting for server on port $port..."
+
+  while true; do
+    if curl -s "localhost:${port}/v1/completions" > /dev/null; then
+      echo "Server on port $port is ready."
+      return 0
+    fi
+
+    local now=$(date +%s)
+    if (( now - start_time >= timeout_seconds )); then
+      echo "Timeout waiting for server on port $port"
+      return 1
+    fi
+
+    sleep 1
+  done
+}
+
+main() {
+    check_required_files
+    check_hf_token
+    check_num_gpus
+    ensure_python_library_installed pandas
+    ensure_python_library_installed datasets
+    ensure_python_library_installed vllm
+    ensure_python_library_installed quart
+
+    trap cleanup INT
+    trap cleanup USR1
+    trap cleanup TERM
+
+    echo "Launching disaggregated serving components..."
+    echo "Please check the log files for detailed output:"
+    echo "  - prefill*.log: Prefill server logs"
+    echo "  - decode*.log: Decode server logs"
+    echo "  - proxy.log: Proxy server log"
+
+    # =============================================================================
+    # Launch Proxy Server
+    # =============================================================================
+    echo ""
+    echo "Starting proxy server on port $PROXY_PORT..."
+    python3 disagg_proxy_p2p_nccl_xpyd.py &
+    PIDS+=($!)
+
+    # Parse GPU and port arrays
+    IFS=',' read -ra PREFILL_GPU_ARRAY <<< "$PREFILL_GPUS"
+    IFS=',' read -ra DECODE_GPU_ARRAY <<< "$DECODE_GPUS"
+    IFS=',' read -ra PREFILL_PORT_ARRAY <<< "$PREFILL_PORTS"
+    IFS=',' read -ra DECODE_PORT_ARRAY <<< "$DECODE_PORTS"
+
+    # =============================================================================
+    # Launch Prefill Servers (X Producers)
+    # =============================================================================
+    echo ""
+    echo "Starting ${#PREFILL_GPU_ARRAY[@]} prefill server(s)..."
+    for i in "${!PREFILL_GPU_ARRAY[@]}"; do
+        local gpu_id=${PREFILL_GPU_ARRAY[$i]}
+        local port=${PREFILL_PORT_ARRAY[$i]}
+        local kv_port=$((21001 + i))
+        
+        echo "  Prefill server $((i+1)): GPU $gpu_id, Port $port, KV Port $kv_port"
+        CUDA_VISIBLE_DEVICES=$gpu_id VLLM_USE_V1=1 vllm serve $MODEL \
+        --enforce-eager \
+        --host 0.0.0.0 \
+        --port $port \
+        --tensor-parallel-size 1 \
+        --seed 1024 \
+        --dtype float16 \
+        --max-model-len 10000 \
+        --max-num-batched-tokens 10000 \
+        --max-num-seqs 256 \
+        --trust-remote-code \
+        --gpu-memory-utilization 0.9 \
+        --disable-log-request \
+        --kv-transfer-config \
+        "{\"kv_connector\":\"P2pNcclConnector\",\"kv_role\":\"kv_producer\",\"kv_buffer_size\":\"1e1\",\"kv_port\":\"$kv_port\",\"kv_connector_extra_config\":{\"proxy_ip\":\"0.0.0.0\",\"proxy_port\":\"$PROXY_PORT\",\"http_port\":\"$port\",\"send_type\":\"PUT_ASYNC\",\"nccl_num_channels\":\"16\"}}" > prefill$((i+1)).log 2>&1 &
+        PIDS+=($!)
+    done
+
+    # =============================================================================
+    # Launch Decode Servers (Y Decoders)
+    # =============================================================================
+    echo ""
+    echo "Starting ${#DECODE_GPU_ARRAY[@]} decode server(s)..."
+    for i in "${!DECODE_GPU_ARRAY[@]}"; do
+        local gpu_id=${DECODE_GPU_ARRAY[$i]}
+        local port=${DECODE_PORT_ARRAY[$i]}
+        local kv_port=$((22001 + i))
+        
+        echo "  Decode server $((i+1)): GPU $gpu_id, Port $port, KV Port $kv_port"
+        VLLM_USE_V1=1 CUDA_VISIBLE_DEVICES=$gpu_id vllm serve $MODEL \
+        --enforce-eager \
+        --host 0.0.0.0 \
+        --port $port \
+        --tensor-parallel-size 1 \
+        --seed 1024 \
+        --dtype float16 \
+        --max-model-len 10000 \
+        --max-num-batched-tokens 10000 \
+        --max-num-seqs 256 \
+        --trust-remote-code \
+        --gpu-memory-utilization 0.7 \
+        --disable-log-request \
+        --kv-transfer-config \
+        "{\"kv_connector\":\"P2pNcclConnector\",\"kv_role\":\"kv_consumer\",\"kv_buffer_size\":\"8e9\",\"kv_port\":\"$kv_port\",\"kv_connector_extra_config\":{\"proxy_ip\":\"0.0.0.0\",\"proxy_port\":\"$PROXY_PORT\",\"http_port\":\"$port\",\"send_type\":\"PUT_ASYNC\",\"nccl_num_channels\":\"16\"}}" > decode$((i+1)).log 2>&1 &
+        PIDS+=($!)
+    done
+
+    # =============================================================================
+    # Wait for All Servers to Start
+    # =============================================================================
+    echo ""
+    echo "Waiting for all servers to start..."
+    for port in "${PREFILL_PORT_ARRAY[@]}" "${DECODE_PORT_ARRAY[@]}"; do
+        if ! wait_for_server $port; then
+            echo "Failed to start server on port $port"
+            cleanup
+            exit 1
+        fi
+    done
+
+    echo ""
+    echo "All servers are up. Starting benchmark..."
+
+    # =============================================================================
+    # Run Benchmark
+    # =============================================================================
+    cd ../../../benchmarks/
+    python3 benchmark_serving.py --port 10001 --seed $(date +%s) \
+        --model $MODEL \
+        --dataset-name random --random-input-len 7500 --random-output-len 200 \
+        --num-prompts 200 --burstiness 100 --request-rate 2 | tee benchmark.log
+
+    echo "Benchmarking done. Cleaning up..."
+
+    cleanup
+}
+
+main
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