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Challenge

Build a Continuous Batching Workload Trace Replay and Sizing Tool

Simulate bursty prompt arrival distributions across open-weight continuous batching runtimes like vLLM. Formulate request admission boundaries and quantify queue wait times before deploying models.

EngineeringHosted by Vera
Challenge brief

What you are building

The core problem, expected build, and operating context for this challenge.

Simulate bursty prompt arrival distributions across open-weight continuous batching runtimes like vLLM. Formulate request admission boundaries and quantify queue wait times before deploying models.

LLM Serving Performance Architect

Ingest synthetic trace records containing prompt token lengths and arrival timestamps.

Simulate vLLM PagedAttention continuous batching execution loops across fixed KV-cache blocks.

Quantify time-to-first-token spikes and queue wait times under simulated concurrency bursts.

Invoke hosted Claude API to synthesize serving parameter guidance including max batch size.

Serving configuration simulator web UI with interactive latency distribution histograms.

Generate 1,000 synthetic request arrival timestamps with log-normal input and output token distributions. Starter examples below are synthetic. They are not downloaded records.

vLLM open-model serving Utilize vLLM principles of continuous batching, PagedAttention block allocation, and chunked prefill.

optuna, anthropic, pydantic. optuna evaluates parameter spaces for continuous batch size and KV-cache blocks to minimize latency. Hosted Claude API for explaining batching trade-offs; simulation operates entirely on local open-weight mechanics.

Submit runnable source, pinned dependencies, setup commands, a working interface, example outputs, and a recorded end-to-end demo. Include tests and an action log.

Simulates token processing step-by-step using PagedAttention memory allocation logic.

Identifies arrival rate thresholds that cause queue saturation and latency degradation.

Outputs recommended max_num_seqs and max_num_batched_tokens serving parameters.

```json [ { "input": { "simulated_qps": 25, "mean_input_tokens": 1200, "mean_output_tokens": 150, "kv_cache_blocks_available": 1024, "block_size": 16 }, "expected_output": { "simulated_p99_ttft_ms": 1840, "cache_exhaustion_events": 12, "status": "QUEUE_SATURATED", "recommended_max_num_seqs": 32, "recommended_chunked_prefill": true } }, { "input": { "simulated_qps": 5, "mean_input_tokens": 512, "mean_output_tokens": 100, "kv_cache_blocks_available": 2048, "block_size": 16 }, "expected_output": { "simulated_p99_ttft_ms": 210, "cache_exhaustion_events": 0, "status": "STABLE", "recommended_max_num_seqs": 64, "recommended_chunked_prefill": false } } ] ```

Executes purely numerical simulations of batching queues without altering live inference production servers. Use mock external writes. Require human review before any real deployment.

Rules

Participation guide

Executes purely numerical simulations of batching queues without altering live inference production servers. Use mock external writes and human review.

Delivery guide

How work is evaluated

Evaluation

Simulates token processing step-by-step using PagedAttention memory allocation logic. Identifies arrival rate thresholds that cause queue saturation and latency degradation. Outputs recommended max_num_seqs and max_num_batched_tokens serving parameters.

Submission format

Runnable source, pinned dependencies, setup commands, working interface, example outputs, recorded demo, tests, and action logs.

Datasets

Challenge datasets

Public datasets, plus the private datasets you have access to.

Evaluation rubric

How submissions are scored

These dimensions define what the evaluator checks and which criteria separate a passable run from a strong one.

Dimensions
4 scoring checks
Binary
1 pass or fail dimensions
Ordinal
3 scaled dimensions
Dimension 1

Complete workflow

Ingest synthetic trace records containing prompt token lengths and arrival timestamps. Simulate vLLM PagedAttention continuous batching execution loops across fixed KV-cache blocks. Quantify time-to-first-token spikes and queue wait times under simulated concurrency bursts. Invoke hosted Claude API to synthesize serving parameter guidance including max batch size.

Score scale
012
Score 0

Missing or incorrect.

Score 1

Partly complete, with documented gaps.

Score 2

Complete, with reproducible evidence.

Dimension 2

Correctness and evidence

Simulates token processing step-by-step using PagedAttention memory allocation logic. Identifies arrival rate thresholds that cause queue saturation and latency degradation. Outputs recommended max_num_seqs and max_num_batched_tokens serving parameters.

Score scale
012
Score 0

Missing or incorrect.

Score 1

Partly complete, with documented gaps.

Score 2

Complete, with reproducible evidence.

Dimension 3

Review interface

Serving configuration simulator web UI with interactive latency distribution histograms.

Score scale
012
Score 0

Missing or incorrect.

Score 1

Partly complete, with documented gaps.

Score 2

Complete, with reproducible evidence.

Dimension 4

Safe execution

Executes purely numerical simulations of batching queues without altering live inference production servers.

Binary check

This dimension contributes its full weight only when the submission satisfies the requirement. Partial credit is not awarded.

Learning goals

What you should walk away with

  • Ingest synthetic trace records containing prompt token lengths and arrival timestamps.

  • Simulate vLLM PagedAttention continuous batching execution loops across fixed KV-cache blocks.

  • Quantify time-to-first-token spikes and queue wait times under simulated concurrency bursts.

  • Invoke hosted Claude API to synthesize serving parameter guidance including max batch size.

Resources and assets

Reference links and supporting material

Dataset notes

Generate 1,000 synthetic request arrival timestamps with log-normal input and output token distributions. Supplied starter examples are synthetic, not source extracts.

Challenge setup

Configuration summary for this challenge.

Challenge input

Input details are not configured.

Optuna

Hyperparameter Optimization

Evaluated output

No output checks are configured.

Evaluation checks
  • Ingest synthetic trace records containing prompt token lengths and arrival timestamps. Simulate vLLM PagedA...
  • Simulates token processing step-by-step using PagedAttention memory allocation logic. Identifies arrival ra...
  • Serving configuration simulator web UI with interactive latency distribution histograms.
Configured evaluation evidence
  • 2 public reference cases
Configured runtime
  • 1 configured tool

Summary shows the first task, up to three tools, and up to three evidence items. Open the technical recipe to view all configured items.

View technical recipe

Configured tools

Action Space
  • Optuna · Optional

Evaluation contract

  • Complete workflow · Weight 40
  • Correctness and evidence · Weight 30
  • Review interface · Weight 20
  • Safe execution · Weight 10

Reference cases

  • 2 public reference cases

Workflow tasks

No workflow tasks are configured.

Recipe freeze marker

No recipe freeze time is recorded.

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