[CI] Add Async Eplb nightly CI tests (#29385)

Signed-off-by: David Chen <530634352@qq.com>
Signed-off-by: WeiQing Chen <40507679+david6666666@users.noreply.github.com>
Co-authored-by: Cyrus Leung <tlleungac@connect.ust.hk>

.buildkite/scripts/scheduled_integration_test/deepseek_v2_lite_ep_async_eplb.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+set -euxo pipefail
+
+# args: [THRESHOLD] [NUM_QUESTIONS] [START_PORT]
+THRESHOLD=${1:-0.25}
+NUM_Q=${2:-1319}
+PORT=${3:-8030}
+OUT_DIR=${OUT_DIR:-/tmp/vllm-scheduled}
+mkdir -p "${OUT_DIR}"
+
+wait_for_server() {
+  local port=$1
+  timeout 600 bash -c '
+    until curl -sf "http://127.0.0.1:'"$port"'/health" > /dev/null; do
+      sleep 1
+    done'
+}
+
+MODEL="deepseek-ai/DeepSeek-V2-lite"
+
+# Set BACKENDS based on platform
+if command -v rocm-smi &> /dev/null || [[ -d /opt/rocm ]] || [[ -n "${ROCM_PATH:-}" ]]; then
+  # ROCm platform
+  BACKENDS=("allgather_reducescatter")
+  # Disable MOE padding for ROCm since it is causing eplb to fail
+  export VLLM_ROCM_MOE_PADDING=0
+else
+  # Non-ROCm platform (CUDA/other)
+  BACKENDS=("deepep_high_throughput" "deepep_low_latency")
+fi
+
+cleanup() {
+  if [[ -n "${SERVER_PID:-}" ]] && kill -0 "${SERVER_PID}" 2>/dev/null; then
+    kill "${SERVER_PID}" 2>/dev/null || true
+    for _ in {1..20}; do
+      kill -0 "${SERVER_PID}" 2>/dev/null || break
+      sleep 0.5
+    done
+    kill -9 "${SERVER_PID}" 2>/dev/null || true
+  fi
+}
+trap cleanup EXIT
+
+for BACK in "${BACKENDS[@]}"; do
+  VLLM_DEEP_GEMM_WARMUP=skip \
+  VLLM_ALL2ALL_BACKEND=$BACK \
+  vllm serve "$MODEL" \
+    --enforce-eager \
+    --tensor-parallel-size 2 \
+    --data-parallel-size 2 \
+    --enable-expert-parallel \
+    --enable-eplb \
+    --eplb-config '{"window_size":200,"step_interval":600,"use_async":true}' \
+    --trust-remote-code \
+    --max-model-len 2048 \
+    --port $PORT &
+  SERVER_PID=$!
+  wait_for_server $PORT
+
+  TAG=$(echo "$MODEL" | tr '/: \\n' '_____')
+  OUT="${OUT_DIR}/${TAG}_${BACK}_async_eplb.json"
+  python3 tests/evals/gsm8k/gsm8k_eval.py --host http://127.0.0.1 --port $PORT --num-questions ${NUM_Q} --save-results ${OUT}
+  python3 - <<PY
+import json; acc=json.load(open('${OUT}'))['accuracy']
+print(f"${MODEL} ${BACK}: accuracy {acc:.3f}")
+assert acc >= ${THRESHOLD}, f"${MODEL} ${BACK} accuracy {acc}"
+PY
+
+  cleanup
+  SERVER_PID=
+  sleep 1
+  PORT=$((PORT+1))
+done

.buildkite/scripts/scheduled_integration_test/deepseek_v2_lite_ep_eplb.sh

@@ -50,6 +50,7 @@ for BACK in "${BACKENDS[@]}"; do
     --data-parallel-size 2 \
     --enable-expert-parallel \
     --enable-eplb \
+    --eplb-config '{"window_size":200,"step_interval":600}' \
     --trust-remote-code \
     --max-model-len 2048 \
     --port $PORT &

.buildkite/scripts/scheduled_integration_test/qwen3_next_mtp_async_eplb.sh

@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+set -euxo pipefail
+
+# args: [THRESHOLD] [NUM_QUESTIONS] [START_PORT]
+THRESHOLD=${1:-0.25}
+NUM_Q=${2:-1319}
+PORT=${3:-8040}
+OUT_DIR=${OUT_DIR:-/tmp/vllm-scheduled}
+mkdir -p "${OUT_DIR}"
+
+wait_for_server() {
+  local port=$1
+  timeout 600 bash -c '
+    until curl -sf "http://127.0.0.1:'"$port"'/health" > /dev/null; do
+      sleep 1
+    done'
+}
+
+MODEL="Qwen/Qwen3-Next-80B-A3B-Instruct"
+
+# Set BACKENDS based on platform
+if command -v rocm-smi &> /dev/null || [[ -d /opt/rocm ]] || [[ -n "${ROCM_PATH:-}" ]]; then
+  # ROCm platform
+  BACKENDS=("allgather_reducescatter")
+  # Disable MOE padding for ROCm since it is causing eplb to fail
+  export VLLM_ROCM_MOE_PADDING=0
+else
+  # Non-ROCm platform (CUDA/other)
+  BACKENDS=("deepep_high_throughput" "deepep_low_latency")
+fi
+
+cleanup() {
+  if [[ -n "${SERVER_PID:-}" ]] && kill -0 "${SERVER_PID}" 2>/dev/null; then
+    kill "${SERVER_PID}" 2>/dev/null || true
+    for _ in {1..20}; do
+      kill -0 "${SERVER_PID}" 2>/dev/null || break
+      sleep 0.5
+    done
+    kill -9 "${SERVER_PID}" 2>/dev/null || true
+  fi
+}
+trap cleanup EXIT
+
+for BACK in "${BACKENDS[@]}"; do
+  VLLM_DEEP_GEMM_WARMUP=skip \
+  VLLM_ALL2ALL_BACKEND=$BACK \
+  vllm serve "$MODEL" \
+    --enforce-eager \
+    --tensor-parallel-size 4 \
+    --enable-expert-parallel \
+    --enable-eplb \
+    --eplb-config '{"window_size":200,"step_interval":600,"use_async":true}' \
+    --speculative-config '{"method":"qwen3_next_mtp","num_speculative_tokens":1}' \
+    --trust-remote-code \
+    --max-model-len 2048 \
+    --gpu-memory-utilization 0.9 \
+    --port $PORT &
+  SERVER_PID=$!
+  wait_for_server $PORT
+
+  TAG=$(echo "$MODEL" | tr '/: \\n' '_____')
+  OUT="${OUT_DIR}/${TAG}_${BACK}.json"
+  python3 tests/evals/gsm8k/gsm8k_eval.py --host http://127.0.0.1 --port $PORT --num-questions ${NUM_Q} --save-results ${OUT}
+  python3 - <<PY
+import json; acc=json.load(open('${OUT}'))['accuracy']
+print(f"${MODEL} ${BACK}: accuracy {acc:.3f}")
+assert acc >= ${THRESHOLD}, f"${MODEL} ${BACK} accuracy {acc}"
+PY
+
+  cleanup
+  SERVER_PID=
+  sleep 1
+  PORT=$((PORT+1))
+done

.buildkite/test-pipeline.yaml

@@ -1373,4 +1373,22 @@ steps:
   num_gpus: 2
   working_dir: "/vllm-workspace"
   commands:
-  - bash .buildkite/scripts/scheduled_integration_test/qwen30b_a3b_fp8_block_ep_eplb.sh 0.8 200 8020 2 1
+  - bash .buildkite/scripts/scheduled_integration_test/qwen30b_a3b_fp8_block_ep_eplb.sh 0.8 200 8020 2 1
+
+- label: DeepSeek V2-Lite Async EPLB Accuracy
+  timeout_in_minutes: 60
+  gpu: h100
+  optional: true
+  num_gpus: 4
+  working_dir: "/vllm-workspace"
+  commands:
+  - bash .buildkite/scripts/scheduled_integration_test/deepseek_v2_lite_ep_async_eplb.sh 0.25 1319 8030
+
+- label: Qwen3-Next-80B-A3B-Instruct MTP Async EPLB Accuracy
+  timeout_in_minutes: 60
+  gpu: h100
+  optional: true
+  num_gpus: 4
+  working_dir: "/vllm-workspace"
+  commands:
+  - bash .buildkite/scripts/scheduled_integration_test/qwen3_next_mtp_async_eplb.sh 0.8 1319 8040

vllm/distributed/eplb/rebalance_execute.py

@@ -322,9 +322,6 @@ async def transfer_layer(
     num_local_physical_experts = next(iter(expert_weights[0])).shape[0]
     assert new_global_expert_indices.shape == (num_moe_layers, num_physical_experts)
     assert num_physical_experts == ep_size * num_local_physical_experts
-    # A buffer to hold the expert weights in one layer during the exchange.
-    # NOTE: Currently we assume the same weights across different layers
-    # have the same shape.
 
     is_unchanged, is_received_locally, experts_recv_loc = move_to_buffer(
         num_local_experts=num_local_physical_experts,