[KV Connector][Mooncake] Pipeline-parallel support for PD-disaggregated serving with Mooncake connector

[HanHan009527]

Purpose

This PR adds Mooncake-specific support for pipeline-parallel prefill in PD-disaggregated serving. It is intended for long-context workloads where the prefill side needs PP to fit or run efficiently on H20-class devices.
Decode-side PP is intentionally not part of this PR.

Test Plan

Unit tests

Run the Mooncake unit suites from a Kubernetes validation pod using the PR source checkout:

python3 -m pytest -v --tb=short \
  tests/v1/kv_connector/unit/test_mooncake_connector.py \
  tests/v1/kv_connector/unit/test_mooncake_connector_hma.py \
  tests/v1/kv_connector/unit/test_mooncake_stats.py \
  tests/v1/kv_connector/unit/test_mooncake_store_connector.py \
  tests/v1/kv_connector/unit/test_mooncake_store_coordinator.py \
  tests/v1/kv_connector/unit/test_mooncake_store_hma_e2e.py \
  tests/v1/kv_connector/unit/test_mooncake_store_scheduler.py \
  tests/v1/kv_connector/unit/test_mooncake_store_worker.py

GLM-5.1-FP8 E2E smoke

Use the vLLM router path with GLM-5.1-FP8 and prefill-side PP. This is the 2-prefill-node / 2-decode-node GLM validation shape:

source: https://github.com/HanHan009527/vllm.git, ref codex/pr/mooncake-pp-transfer
source commit: f91d4527d18bff47bab69a71e08518e767e63d51
model path: /data/models/GLM-5.1-FP8
served model: glm-5
router: vllm-router, OpenAI-compatible /v1 path
connector: MooncakeConnector / mooncake

Selected startup args for the GLM validation deployment:

prefill vllm serve:
  vllm serve /data/models/GLM-5.1-FP8
  --host 0.0.0.0
  --port 18080
  --served-model-name glm-5
  --trust-remote-code
  --tokenizer-mode auto
  --tool-call-parser glm47
  --enable-auto-tool-choice
  --reasoning-parser glm45
  --kv-cache-dtype fp8
  --block-size 64
  --data-parallel-size 1
  --nnodes 2
  --node-rank ${VLLM_NODE_RANK}
  --master-addr 192.168.122.128
  --master-port 21000
  --distributed-executor-backend mp
  --tensor-parallel-size 8
  --pipeline-parallel-size 2
  --max-num-batched-tokens 8192
  --max-num-seqs 8
  --enforce-eager
  --no-disable-hybrid-kv-cache-manager
  --disable-uvicorn-access-log
  --gpu-memory-utilization 0.80
  --quantization fp8
  --aggregate-engine-logging
  --kv-transfer-config '{"kv_connector":"MooncakeConnector","kv_role":"kv_producer","kv_load_failure_policy":"fail","kv_buffer_device":"cuda","kv_connector_extra_config":{"enforce_handshake_compat":false,"mooncake_protocol":"rdma"}}'
  env: VLLM_MOONCAKE_BOOTSTRAP_PORT=18998

decode vllm serve:
  vllm serve /data/models/GLM-5.1-FP8
  --host 0.0.0.0
  --port 18081
  --served-model-name glm-5
  --trust-remote-code
  --tokenizer-mode auto
  --tool-call-parser glm47
  --enable-auto-tool-choice
  --reasoning-parser glm45
  --kv-cache-dtype fp8
  --block-size 64
  --data-parallel-size 1
  --nnodes 2
  --node-rank ${VLLM_NODE_RANK}
  --master-addr 192.168.122.95
  --master-port 21000
  --distributed-executor-backend mp
  --tensor-parallel-size 16
  --max-num-batched-tokens 1024
  --max-num-seqs 64
  --enforce-eager
  --no-disable-hybrid-kv-cache-manager
  --disable-uvicorn-access-log
  --gpu-memory-utilization 0.95
  --quantization fp8
  --aggregate-engine-logging
  --kv-transfer-config '{"kv_connector":"MooncakeConnector","kv_role":"kv_consumer","kv_load_failure_policy":"fail","kv_buffer_device":"cuda","kv_connector_extra_config":{"enforce_handshake_compat":false,"mooncake_protocol":"rdma"}}'
  env: VLLM_MOONCAKE_BOOTSTRAP_PORT=18999

router:
  vllm-router
  --policy round_robin
  --prefill-policy round_robin
  --decode-policy round_robin
  --vllm-pd-disaggregation
  --prefill http://192.168.122.128:18080 18998
  --decode http://192.168.122.95:18081
  --host 0.0.0.0
  --port 30081
  --kv-connector mooncake
  --request-timeout-secs 7200
  --health-check-interval-secs 10
  --disable-circuit-breaker

Topology:

prefill:
  nodes: 2
  TP=8, PP=2

decode:
  nodes: 2
  TP=16, PP=1
  DP=1

GSM8K-64 accuracy smoke

Run the vLLM repo GSM8K script through the same router endpoint:

timeout 1800 python3 tests/evals/gsm8k/gsm8k_eval.py \
  --host http://127.0.0.1 \
  --port 30081 \
  --num-questions 64 \
  --num-shots 5 \
  --max-tokens 256 \
  --temperature 0 \
  --seed 42 \
  --save-results /tmp/vllm-gsm8k-results/gsm8k-64-vllm-official-f91d4527.json

This is a lightweight accuracy smoke, not full GSM8K accuracy.

Cold long-input TTFT smoke

Use vLLM's benchmark client against the same vLLM router path, with no prefix-cache reuse and one generated token:

vllm bench serve \
  --backend openai \
  --base-url http://127.0.0.1:30081 \
  --endpoint /v1/completions \
  --model glm-5 \
  --served-model-name glm-5 \
  --tokenizer /data/models/GLM-5.1-FP8 \
  --trust-remote-code \
  --dataset-name random \
  --random-input-len 32000 \
  --random-output-len 1 \
  --random-range-ratio 0 \
  --num-prompts 1 \
  --request-rate inf \
  --max-concurrency 1 \
  --ignore-eos \
  --temperature 0 \
  --save-result \
  --save-detailed

Test Result

Unit tests

• Result: 162 passed, 19 warnings in 114.28s (0:01:54)

GLM-5.1-FP8 E2E smoke

Smoke result:

curl -sS -w '\nHTTP_STATUS=%{http_code}\n' \
  http://127.0.0.1:30081/v1/chat/completions \
  -H 'Content-Type: application/json' \
  -d '{"model":"glm-5","messages":[{"role":"user","content":"1+1等于几？"}],"temperature":0,"max_tokens":160}'

{"choices":[{"message":{"role":"assistant","content":"1+1等于2。"},"finish_reason":"stop"}],"usage":{"prompt_tokens":16,"completion_tokens":160,"total_tokens":176}}
HTTP_STATUS=200

GSM8K-64 accuracy smoke

Observed result through the same GLM router path:

correct=61/64
accuracy=0.953125

32K cold TTFT smoke

Result:

successful requests: 1
total input tokens: 32000
mean/median/p99 TTFT: 8249.37 ms

full draft for deepseek V4 #45112

---

Essential Elements of an Effective PR Description Checklist

• The purpose of the PR.
• The test plan.
• The test results.
• (Optional) The necessary documentation update.

---

AI assistance was used to prepare this PR. The submitter reviewed the changes and the test evidence.

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @HanHan009527.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[claude]

Claude Code Review

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[NickLucche]

thanks for adding this @HanHan009527 !
Will do a proper round once @dtcccc and friends have validated the approach :)

[zixi-qi]

Thanks for the change! Assuming HMA support is out of scope of this PR for now?

[HanHan009527]

Thanks for the change! Assuming HMA support is out of scope of this PR for now?

Yes, I'm testing the HMA using a draft branch, which I plan to commit as the next pr.

[dtcccc]

LGTM! Thanks for the contribution.

[HanHan009527]

thanks for adding this @HanHan009527 ! Will do a proper round once @dtcccc and friends have validated the approach :)

@NickLucche This PR is okay for @dtcccc. Could you help add the CI tag?

[HanHan009527]

The failed CI doesn't seem to be relevant. Could you help take a look at this PR when you have time? @NickLucche