disagg_router.sh

#!/bin/bash
# SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: Apache-2.0
#
# Disaggregated serving with KV-aware routing: 2 prefill + 2 decode workers.
# GPUs: 4

set -e
trap 'echo Cleaning up...; kill 0' EXIT

SCRIPT_DIR="$(dirname "$(readlink -f "$0")")"
source "$SCRIPT_DIR/../../../common/launch_utils.sh"

# Parse command line arguments
ENABLE_OTEL=false
while [[ $# -gt 0 ]]; do
    case $1 in
        --enable-otel)
            ENABLE_OTEL=true
            shift
            ;;
        -h|--help)
            echo "Usage: $0 [OPTIONS]"
            echo "Options:"
            echo "  --enable-otel        Enable OpenTelemetry tracing"
            echo "  -h, --help           Show this help message"
            echo ""
            echo "Note: System metrics are enabled by default on ports:"
            echo "  8081-8082 (prefill workers), 8083-8084 (decode workers)"
            exit 0
            ;;
        *)
            echo "Unknown option: $1"
            echo "Use --help for usage information"
            exit 1
            ;;
    esac
done

# Enable tracing if requested
TRACE_ARGS=()
if [ "$ENABLE_OTEL" = true ]; then
    export DYN_LOGGING_JSONL=true
    export OTEL_EXPORT_ENABLED=1
    export OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=${OTEL_EXPORTER_OTLP_TRACES_ENDPOINT:-http://localhost:4317}
    TRACE_ARGS+=(--enable-trace --otlp-traces-endpoint localhost:4317)
fi

MODEL="Qwen/Qwen3-0.6B"
HTTP_PORT="${DYN_HTTP_PORT:-8000}"
print_launch_banner "Launching Disaggregated + KV Routing (4 GPUs)" "$MODEL" "$HTTP_PORT"

# Start frontend with KV routing
# The frontend will automatically detect prefill workers and activate an internal prefill router
# No standalone prefill router needed - the frontend handles prefill routing internally
# dynamo.frontend accepts either --http-port flag or DYN_HTTP_PORT env var (defaults to 8000)
OTEL_SERVICE_NAME=dynamo-frontend \
python3 -m dynamo.frontend \
    --router-mode kv \
    --router-reset-states &

# NOTE: Each worker picks a random NCCL port (get_free_port) for torch.distributed.
# This has a TOCTOU race — the port can be grabbed before init_process_group binds it,
# causing sporadic EADDRINUSE.  Pass --nccl-port <unique_port> per worker to avoid this.

# run prefill worker
OTEL_SERVICE_NAME=dynamo-worker-prefill-1 DYN_SYSTEM_PORT=${DYN_SYSTEM_PORT1:-8081} \
python3 -m dynamo.sglang \
  --model-path Qwen/Qwen3-0.6B \
  --served-model-name Qwen/Qwen3-0.6B \
  --page-size 64 \
  --tp 1 \
  --trust-remote-code \
  --disaggregation-mode prefill \
  --host 0.0.0.0 \
  --kv-events-config '{"publisher":"zmq","topic":"kv-events","endpoint":"tcp://*:5557"}' \
  --disaggregation-transfer-backend nixl \
  --enable-metrics \
  --disable-piecewise-cuda-graph \
  "${TRACE_ARGS[@]}" &

# run prefill worker
OTEL_SERVICE_NAME=dynamo-worker-prefill-2 DYN_SYSTEM_PORT=${DYN_SYSTEM_PORT2:-8082} \
CUDA_VISIBLE_DEVICES=1 python3 -m dynamo.sglang \
  --model-path Qwen/Qwen3-0.6B \
  --served-model-name Qwen/Qwen3-0.6B \
  --page-size 64 \
  --tp 1 \
  --trust-remote-code \
  --disaggregation-mode prefill \
  --host 0.0.0.0 \
  --kv-events-config '{"publisher":"zmq","topic":"kv-events","endpoint":"tcp://*:5558"}' \
  --disaggregation-transfer-backend nixl \
  --enable-metrics \
  --disable-piecewise-cuda-graph \
  "${TRACE_ARGS[@]}" &

# run decode worker
OTEL_SERVICE_NAME=dynamo-worker-decode-1 DYN_SYSTEM_PORT=${DYN_SYSTEM_PORT3:-8083} \
CUDA_VISIBLE_DEVICES=3 python3 -m dynamo.sglang \
  --model-path Qwen/Qwen3-0.6B \
  --served-model-name Qwen/Qwen3-0.6B \
  --page-size 64 \
  --tp 1 \
  --trust-remote-code \
  --disaggregation-mode decode \
  --host 0.0.0.0 \
  --kv-events-config '{"publisher":"zmq","topic":"kv-events","endpoint":"tcp://*:5560"}' \
  --disaggregation-transfer-backend nixl \
  --enable-metrics \
  --disable-piecewise-cuda-graph \
  "${TRACE_ARGS[@]}" &

# run decode worker
OTEL_SERVICE_NAME=dynamo-worker-decode-2 DYN_SYSTEM_PORT=${DYN_SYSTEM_PORT4:-8084} \
CUDA_VISIBLE_DEVICES=2 python3 -m dynamo.sglang \
  --model-path Qwen/Qwen3-0.6B \
  --served-model-name Qwen/Qwen3-0.6B \
  --page-size 64 \
  --tp 1 \
  --trust-remote-code \
  --disaggregation-mode decode \
  --host 0.0.0.0 \
  --kv-events-config '{"publisher":"zmq","topic":"kv-events","endpoint":"tcp://*:5559"}' \
  --disaggregation-transfer-backend nixl \
  --enable-metrics \
  --disable-piecewise-cuda-graph \
  "${TRACE_ARGS[@]}" &

# Wait for any worker to exit (keeps script running)
# Exit on first worker failure; kill 0 in the EXIT trap tears down the rest
wait_any_exit