---
license: apache-2.0
base_model: Qwen/Qwen3-8B
tags:
  - reinforcement-learning
  - grpo
  - infrastructure-management
  - sre
  - kubernetes
  - lora
  - unsloth
  - trl
language:
  - en
pipeline_tag: text-generation
---

# Qwen3-8B — GRPO Fine-tuned on DIME

**Qwen3-8B fine-tuned via Group Relative Policy Optimization (GRPO) to act as an autonomous Site-Reliability Engineer in a simulated 8-node Kubernetes cluster.**

---

## What is this model?

This is a **merged BF16 checkpoint** of [Qwen/Qwen3-8B](https://huggingface.co/Qwen/Qwen3-8B) after 300 steps of GRPO fine-tuning on the DIME (Distributed Infrastructure Management Environment) benchmark — trained in **44 minutes on a single A100-SXM4-80GB**.

The model observes per-node CPU, memory, queue depths, and tail-latency telemetry, then outputs a single `kubectl` command to maintain cluster health. It was trained from scratch with a completely redesigned reward signal after the original reward function was found to produce zero-variance advantages that blocked all gradient flow.

---

## Benchmark Results

**+44.2% relative improvement over zero-shot Qwen3-8B** on the 14-task DIME benchmark.

![Benchmark comparison](fig3_benchmark.png)

| Metric | Zero-shot | Fine-tuned |
|---|---|---|
| Overall avg score | 0.394 | **0.569** (best episode) |
| connection_pool_deadlock | 0.630 | **0.976** |
| memory_leak_slow_burn | 0.990 | **0.990** |
| node_failure | 0.220 | **0.920** |
| retry_storm | 0.377 | **0.587** |
| thundering_herd | 0.393 | **0.606** |
| traffic_spike | 0.024 | **0.399** |

---

## The Reward Engineering Challenge

The central technical contribution is replacing a **gradient-blocking reward cliff** with a differentiable seven-component signal.

The original reward returned `r = −1000` whenever the database node failed — which happened within the first 3 steps of most episodes. With all rewards identical, GRPO advantages collapsed to zero and no gradient flowed.

![Reward cliff vs bounded signal](fig1_reward_cliff.png)

The fixed reward:

$$R_{env}(s,a) = \text{clip}(\, r_{topo} + r_{shed} + r_{mem} + r_{fric} + r_{lat} + r_{up} + r_{eff},\; -5,\; +5 \,)$$

with bounded components ensuring non-zero gradient everywhere.

---

## DIME Environment

![DIME architecture](fig4_dime_architecture.png)

- **8-node cluster**: node-0 is a stateful PostgreSQL DB (SPOF), nodes 1–7 are stateless workers
- **Partial observability**: telemetry dropout when `cpu_i = −1`
- **6 action types**: restart, reroute, scale_up, throttle, query_logs, no_op
- **14 failure scenarios**: traffic spikes, node failures, memory leaks, retry storms, split-brain, and more
- **Error budget**: throttle burns irreplaceable budget; the agent must be economical

---

## Training Dynamics

![Training curves](fig2_training_curves.png)

- `reward_format` reached 3.0 (perfect) from step 1 — the model learned XML scaffold immediately
- `reward_validity` stabilised at 1.9+ — no invalid commands after step ~10
- `reward_env` improved steadily — environment physics signal dominated learning
- `clipped_ratio` stayed near 0 throughout — healthy PPO clip utilisation
- Total wall-clock: **44 minutes** at 8.4 s/step

---

## Triage Oracle and the Priority Inversion Bug

The model is guided during training by a 10-rule deterministic triage tree:

![Triage tree](fig7_triage_tree.png)

A critical discovery: the original oracle evaluated the **Black Swan rule** (`|F(s)| ≥ 2 → throttle(0.3)`) *before* the **DB Recovery rule** (`0 ∈ F(s) → restart_node(0)`). When multiple nodes including the database were failed, the oracle prescribed `throttle` instead of `restart_node(0)`. The model faithfully learned this suboptimal policy. Fixing the priority ordering accounted for **+0.044 benchmark score** improvement.

---

## Failure Modes Documented

Five training configurations failed before convergence — each diagnosable from standard TRL metrics:

![Failure modes](fig6_failure_modes.png)

| Run | Failure | Signal |
|---|---|---|
| vLLM on A100-40GB | SM 8.0 segfault (`compilation_config` not set) | Crash at init |
| batch=4, gen=8 | CPU-bound rewards; 126 s/step, GPU idle | `samples/sec = 0.06` |
| max_comp=256 | `<think>` blocks truncated before `</think>` | `frac_reward_zero_std = 1.0` |
| reward_env×2 | 10:1 env-to-triage ratio recreated zero-variance | `zero_std → 1.0` at step 119 |
| oracle inverted | Learned `throttle` in DB-failure states | Low `triage/mean` |

---

## Reward Components

![Reward components](fig5_reward_components.png)

```
R(a,s) = R_fmt [-3,+3]  +  R_val [-2,+2]  +  R_env [-5,+5]  +  R_tri [-0.5,+1]
```

- **R_fmt**: XML scaffold compliance (`<reasoning>` + `<action>` tags)
- **R_val**: Syntactic kubectl parse success
- **R_env**: 7-component physics reward (topology, latency, memory, uptime, budget)
- **R_tri**: Oracle triage alignment (gentle guidance, not primary teacher)

---

## Quick Start

```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model = AutoModelForCausalLM.from_pretrained(
    "Naseer-010/Qwen3-8B-Finetuned-DIME",
    torch_dtype="bfloat16",
    device_map="auto",
)
tokenizer = AutoTokenizer.from_pretrained("Naseer-010/Qwen3-8B-Finetuned-DIME")

system_prompt = """You are an autonomous SRE agent managing an 8-node Kubernetes cluster.
Node-0 is the PostgreSQL database (SPOF). Nodes 1-7 are stateless workers.

TRIAGE PRIORITY (check in order):
1. OOM: if any node mem > 0.92 → kubectl delete pod node-<i>
2. DB RECOVERY: if node-0 in failed_nodes → kubectl delete pod node-0
3. SPLIT-BRAIN: if io_wait > 0.80 → kubectl throttle ingress --rate=0.5
4. HOT-SHARD: if one worker cpu > 0.90, others low → reroute traffic
5. RETRY STORM: if p99 > 100ms and rr > 150 → kubectl throttle ingress --rate=0.4
6. ZOMBIE NODE: if worker cpu near 0 → reroute away from it
7. BLACK SWAN: if 2+ nodes failed (DB alive) → kubectl throttle ingress --rate=0.3
8. DB STRESS: if node-0 cpu > 0.80 → kubectl throttle ingress --rate=0.7
9. SAFE SCALE: if avg worker cpu > 0.75 and budget > 20 → scale up
10. HEALTHY → no_op

Output format:
<reasoning>One sentence identifying which rule applies.</reasoning>
<action>{"command": "kubectl ..."}</action>"""

obs = {
    "cpu_loads": [0.45, 0.82, 0.79, 0.88, 0.75, 0.81, 0.77, 0.73],
    "mem_utilizations": [0.41, 0.68, 0.71, 0.65, 0.62, 0.70, 0.66, 0.64],
    "queue_lengths": [12, 45, 41, 53, 38, 44, 40, 37],
    "failed_nodes": [],
    "latency_ms": 187.3,
    "p99_latency": 312.5,
    "request_rate": 1840.0,
    "io_wait": 0.12,
    "error_budget": 85,
    "step": 4,
    "task_hint": "System is under heavy traffic load."
}

import json
messages = [
    {"role": "system", "content": system_prompt},
    {"role": "user", "content": f"Current system state:\n{json.dumps(obs, indent=2)}\nWhat action should be taken?"}
]

text = tokenizer.apply_chat_template(messages, tokenize=False, add_generation_prompt=True)
inputs = tokenizer(text, return_tensors="pt").to(model.device)

outputs = model.generate(
    **inputs,
    max_new_tokens=1024,
    temperature=0.6,
    top_p=0.95,
    do_sample=True,
)
print(tokenizer.decode(outputs[0][inputs["input_ids"].shape[1]:], skip_special_tokens=True))
```

Expected output:
```
<think>
P99 latency is 312ms with request rate 1840 rps and no failed nodes.
Rule 5 (retry storm): p99 > 100ms and rr > 150 → throttle at 0.4.
</think>
<reasoning>Rule 5 applies: p99 latency 312ms exceeds threshold with high request rate 1840 rps — throttle ingress to shed load.</reasoning>
<action>{"command": "kubectl throttle ingress --rate=0.4"}</action>
```

---

## Training Details

| Parameter | Value |
|---|---|
| Base model | `Qwen/Qwen3-8B` (BF16) |
| Method | GRPO (TRL 0.24.0 + Unsloth + vLLM 0.6.3) |
| LoRA rank | 32, alpha=64, all projection layers |
| Trainable params | 1.05% (349 MB adapter) |
| Training steps | 300 |
| Batch size | 1 × 4 generations = 4 completions/step |
| Learning rate | 5e-6, cosine schedule |
| Max completion length | 1024 tokens |
| GPU | A100-SXM4-80GB |
| Wall-clock time | 44 minutes |

---

## Citation

```bibtex
@misc{dime2026,
  title  = {Fine-Tuning Language Models as Autonomous SREs via GRPO: The DIME Benchmark},
  author = {Nithish Sriram and Naseer},
  year   = {2026},
  url    = {https://huggingface.co/Naseer-010/Qwen3-8B-Finetuned-DIME}
}
```

---

*Trained at SRM AP · Hackathon 2026*
