Migration correctness smoke tests: direct-read, partial-transfer, NIXL

Standalone smoke tests validating KV-migration correctness paths before
trace replay: full migrate-cache, partial-prefill transfer, and a
NIXL-connector variant, each with a runner.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

microbench/connector_tax/cache_sweep/run_smoke_nixl.sh

@@ -0,0 +1,73 @@
+#!/usr/bin/env bash
+# Smoke test for Nixl-based PD-sep migration (NVLink intra-node via UCX).
+#
+# Drops 2 vLLM kv_both NixlConnector instances on GPU 0,1 and runs
+# smoke_test_migrate_cache.py against them with the kv_transfer_params
+# format Nixl expects (only do_remote_decode on src; proxy must forward
+# kv_transfer_params from src's response to dst).
+#
+# Since smoke_test_migrate_cache.py is currently hard-coded for Mooncake
+# (transfer_id + remote_bootstrap_addr), we use a tiny Python in-line
+# variant here that does the Nixl response-forward handshake directly.
+
+set -uo pipefail
+
+PROJ_DIR="${PROJ_DIR:-/home/admin/cpfs/wjh/agentic-kv}"
+MODEL="${MODEL:-/home/admin/cpfs/wjh/models/Qwen/Qwen3-Coder-30B-A3B-Instruct}"
+VENV="$PROJ_DIR/.venv/bin"
+LOGS_DIR="${LOGS_DIR:-$PROJ_DIR/outputs/smoke_nixl_$(date +%Y%m%d_%H%M%S)}"
+mkdir -p "$LOGS_DIR"
+
+cleanup() {
+    echo "[smoke-nixl] cleaning up vLLM..."
+    pkill -9 -f "vllm serve" 2>/dev/null || true
+    pkill -9 -f "EngineCore" 2>/dev/null || true
+    sleep 2
+}
+trap cleanup EXIT
+cleanup
+
+echo "[smoke-nixl] starting 2 vLLM kv_both NixlConnector on GPU 0,1"
+for i in 0 1; do
+    port=$((8000 + i))
+    nixl_port=$((5600 + i))
+    master=$((29500 + i))
+    PYTHONHASHSEED=42 \
+    VLLM_NIXL_SIDE_CHANNEL_PORT=$nixl_port \
+    CUDA_VISIBLE_DEVICES=$i \
+    MASTER_PORT=$master \
+    nohup "$VENV/vllm" serve "$MODEL" \
+        --host 0.0.0.0 --port "$port" \
+        --tensor-parallel-size 1 \
+        --trust-remote-code --enable-prefix-caching \
+        --dtype auto --gpu-memory-utilization 0.9 \
+        --max-model-len 200000 \
+        --kv-transfer-config '{"kv_connector":"NixlConnector","kv_role":"kv_both"}' \
+        --enable-prompt-tokens-details \
+        > "$LOGS_DIR/vllm_inst_${i}_gpu${i}.log" 2>&1 &
+    disown
+    sleep 2
+done
+
+echo "[smoke-nixl] waiting for health on 8000 and 8001 ..."
+for port in 8000 8001; do
+    tries=0
+    while ! curl -sf "http://127.0.0.1:$port/health" >/dev/null 2>&1; do
+        tries=$((tries+1))
+        if [ $tries -gt 240 ]; then
+            echo "[smoke-nixl] FATAL: $port not ready"; exit 1
+        fi
+        sleep 2
+    done
+    echo "  port=$port ready"
+done
+
+echo "[smoke-nixl] running smoke_nixl_migrate.py"
+"$VENV/python" "$PROJ_DIR/microbench/connector_tax/cache_sweep/smoke_nixl_migrate.py" \
+    --src-port 8000 --dst-port 8001 \
+    ${EXTRA_SMOKE_ARGS:-} \
+    2>&1 | tee "$LOGS_DIR/smoke_output.log"
+
+ec=${PIPESTATUS[0]}
+echo "[smoke-nixl] test exit=$ec, logs at $LOGS_DIR"
+exit $ec