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homelab/k8s/apps/llm-serving/inferenceservice-ornith.yaml
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Story Crater Bot 4fb1c6feeb feat(gpu): serve 6 models on worker-1 via KServe — vLLM v0.11.0 (bitsandbytes) + Ollama + TEI, plus RuntimeClass/privileged-PSA prereqs and a local-NVMe StorageClass, working around Volta sm_70 limits
Layout on 4x Tesla V100 32GB (PCIe, no NVLink), all TP=1:
  GPU0+1  vLLM    DeepSeek-R1-Distill-Qwen-32B bnb-nf4  (2 replicas)
  GPU2    Ollama  ornith:35b + qwen2.5:3b-instruct      (co-resident)
  GPU3    vLLM    Qwen2.5-Math-PRM-7B                   (reward model)
  CPU     TEI     nomic-embed-text-v2-moe, bge-reranker-base

Volta constraints, each verified against live output rather than config:
- vLLM pinned v0.11.0: sm_70 dropped from CUDA_SUPPORTED_ARCHS at v0.11.1.
- AWQ hard-rejected (needs sm_75). GPTQ passes vLLM's min_capability=60 gate
  but is NUMERICALLY WRONG on sm_70 — emits garbage logits. Proven by an fp16
  control run producing correct text on an identical backend. bitsandbytes nf4
  verified correct by output.
- flashinfer's check_cuda_arch() crashes on any sm_7x (calls .isdigit() on an
  int) -> VLLM_USE_FLASHINFER_SAMPLER=0.
- xformers has no sm_70 kernel for V1's paged-attention bias, and V0 was
  removed in v0.11.0 -> TRITON_ATTN.
- Ornith is Qwen3.5-MoE hybrid-attention; vLLM added that arch after dropping
  Volta, so no build has both -> Ollama, which also multiplexes a second model
  on the same card for free.

Cluster prereqs that were absent:
- RuntimeClass nvidia: the Talos toolkit extension registers the containerd
  handler but not the k8s object; without it every pod is rejected at admission.
- gpu-system pinned to privileged PSA: a device plugin cannot satisfy the
  cluster-default baseline, it must mount hostPath.
- device-plugin affinity=null: the chart requires NFD labels that do not exist
  here, so it matched zero nodes and reported desiredNumberScheduled=0 silently.
- Recreate strategy on GPU services: with GPUs allocated exactly 4/4, a
  RollingUpdate surge pod has no card and deadlocks the rollout.
- longhorn-llm-local SC (1 replica, strict-local, disk tag llm): the default
  3-replica class could not place the volume at all (every control-plane disk
  was at its over-provisioning ceiling), and this keeps ~60GB of weights on
  worker-1's own NVMe instead of reading them over the network.

deploy-gpu-serving.sh sequences ArgoCD syncs (or helm/kubectl in --manual mode)
and never applies a manifest absent from git; doctor/unstick/teardown stages
exist so this is diagnosable without ad-hoc kubectl archaeology.
2026-08-13 07:02:53 -07:00

108 lines
4.2 KiB
YAML

# Action engine — Ornith-1.0-35B on Ollama.
#
# Why not vLLM like the other two: Ornith is
# Qwen3_5MoeForConditionalGeneration (Qwen3.5 MoE, 256 experts / 8 active,
# hybrid attention — 30 linear_attention + 10 full_attention layers). vLLM's
# Qwen3.5 support landed 2026-07-29, AFTER vLLM dropped Volta (sm_70) at
# v0.11.1. No vLLM build has both, so Ornith cannot run on vLLM on a V100.
#
# Ollama ships `ornith:35b` in its library and runs a llama-server runner
# underneath, which keeps Volta support. q4 is ~21GB — fits one 32GB V100 with
# room for KV.
#
# OLLAMA_KEEP_ALIVE=-1 is load-bearing: the harness calls this every loop
# iteration, and Ollama's default is to evict an idle model after 5m, which
# would add a ~21GB reload to a random future request.
apiVersion: serving.kserve.io/v1beta1
kind: InferenceService
metadata:
name: ornith
labels:
app.kubernetes.io/name: llm-ornith
app.kubernetes.io/part-of: llm-serving
spec:
predictor:
minReplicas: 1
# Recreate, not the default RollingUpdate: GPUs are allocated exactly 4/4,
# so a surge pod has no card to claim and sits Pending while the old pod is
# never torn down — a deadlock. Recreate tears down first, accepting a brief
# gap during updates.
deploymentStrategy:
type: Recreate
maxReplicas: 1
nodeSelector:
kubernetes.io/hostname: worker-1
runtimeClassName: nvidia
containers:
- name: kserve-container
image: ollama/ollama:0.32.9@sha256:1685741456770df6e3cceb2a945a5f75e020f658d1701509668d6f4688f1dd3f
# `ollama serve` does not pull models, and `ollama pull` needs a running
# server — so background the server, wait for it, pull, then hand the
# foreground back to serve.
command:
- /bin/sh
- -c
- |
set -e
ollama serve &
SERVE_PID=$!
until ollama list >/dev/null 2>&1; do sleep 2; done
ollama pull ornith:35b
ollama pull qwen2.5:3b-instruct
wait $SERVE_PID
env:
# Match the port the other two engines use.
- name: OLLAMA_HOST
value: "0.0.0.0:8080"
- name: OLLAMA_MODELS
value: /mnt/models/ollama
# Ollama defaults to a 4096 context, far too small for an agentic
# coding model. Ornith's hybrid attention means only 10 of its 40
# layers hold a conventional KV cache, so 32K is affordable in the
# ~11GiB left after its 21GB of weights.
- name: OLLAMA_CONTEXT_LENGTH
value: "32768"
# Never evict — this model is on the harness's hot path.
- name: OLLAMA_KEEP_ALIVE
value: "-1"
# Serial agent loop; no benefit from parallel slots.
- name: OLLAMA_NUM_PARALLEL
value: "1"
# 2, so ornith and the small utility model stay co-resident on GPU2
# instead of evicting one another on every alternating request.
- name: OLLAMA_MAX_LOADED_MODELS
value: "2"
ports:
- containerPort: 8080
protocol: TCP
resources:
requests:
cpu: "8"
memory: 8Gi
nvidia.com/gpu: "1"
limits:
cpu: "16"
memory: 16Gi
nvidia.com/gpu: "1"
volumeMounts:
- name: models
mountPath: /mnt/models
# Probes must confirm the MODEL is present, not just that the server
# answers. Ollama's `GET /` returns 200 ("Ollama is running") the moment
# `ollama serve` binds — which is before the ~21GB pull finishes. An
# httpGet probe would therefore mark this pod Ready with no model
# loaded, and KServe would route traffic to it.
startupProbe:
exec:
command: ["/bin/sh", "-c", "ollama list 2>/dev/null | grep -q ornith && ollama list 2>/dev/null | grep -q qwen2.5"]
periodSeconds: 15
failureThreshold: 120
readinessProbe:
exec:
command: ["/bin/sh", "-c", "ollama list 2>/dev/null | grep -q ornith && ollama list 2>/dev/null | grep -q qwen2.5"]
periodSeconds: 10
volumes:
- name: models
persistentVolumeClaim:
claimName: llm-models