rbachkaniwala3/stream2llm-data

Stream2LLM Dataset

Dataset for the paper: Stream2LLM: Overlap Context Streaming and Prefill for Reduced Time-to-First-Token (MLSys 2026 artifact evaluation). Contains workload traces, experiment run logs, and performance model measurements used to produce all figures, tables, and inline numbers in the paper.

This repository is a git submodule of the main Stream2LLM artifact (branch: mlsys_artifact). Clone the parent repo with --recurse-submodules to automatically fetch this data.

Directory Structure

data/
├── anns/                          # ANNS workload data
│   ├── res/                       # 4,997 pipeline trace CSVs
│   ├── retrieved_corpus_content.*.json  # Corpus content shards
│   ├── query_trace_map_5k.json    # Query-to-trace mapping
│   └── compute_workload_stats.py  # Workload statistics script
├── crawl/                         # Crawler workload data
│   ├── traces/simpleQA_ALL/       # 4,322 query trace CSVs
│   └── compute_workload_stats.py  # Workload statistics script
├── perf_model/                    # Performance model measurements
│   ├── recomputation/             # 7 recomputation latency JSONs
│   └── swap/                      # 11 swap latency JSONs
└── run_log/                       # Experiment run logs
    ├── crawler/                   # 5 crawler experiment configurations
    └── anns/                      # 5 ANNS experiment configurations

Workload Traces

ANNS (anns/res/)

4,997 pipeline trace files from approximate nearest neighbor search workloads. Each file is named _L10000_W8_query<ID>_pipeline_trace.csv and contains:

Column	Description
StartTime_us	Chunk start time in microseconds
EndTime_us	Chunk end time in microseconds
StartIteration	Starting iteration index
EndIteration	Ending iteration index
PipelinePool	Tuple of candidate IDs in the pipeline pool

Each row represents a chunk arrival — a batch of ANNS iterations that produces new candidate results. Queries have 1–26 chunks (median 4), with inter-chunk arrival times ranging from sub-millisecond to ~9 seconds (median 37 ms).

Crawler (crawl/traces/simpleQA_ALL/)

4,322 query trace files from a web crawling workload (SimpleQA question-answering). Each file is named query_<ID>.csv and contains:

Column	Description
type	Event type: tavily_search or page_scrape
startTime	Event start time in seconds
endTime	Event end time in seconds
query	The original query string (on search rows)
links_found	Number of links returned by search
url	URL scraped (on page_scrape rows)
content_length	Length of scraped content in characters
content	Scraped page text
link_idx	Index of the link being scraped

Each row is a chunk event. The first row is typically a tavily_search followed by page_scrape events. Queries have 1–17 chunks (median 8), with inter-chunk arrival times of 3 ms to ~35 seconds (median 701 ms).

Performance Model (perf_model/)

Microbenchmark measurements for KV cache eviction cost modeling, collected across multiple GPU types (A40, A100, H100, H200) and model configurations (8B, 70B with varying tensor parallelism).

• recomputation/: Recomputation latency in ms, keyed by number of tokens recomputed (e.g., 16, 32, ..., 8192). Each key maps to an array of repeated measurements.
• swap/: Swap (CPU↔GPU transfer) latency in ms, same key structure. Files ending in _kernel_latency.json contain kernel-only timings; others include end-to-end transfer overhead.

Hardware configurations: A40, A100, H100_tp2, H100_tp4_70B, H200_tp2, H200_tp4_70B.

Run Logs (run_log/)

Experiment outputs from the Stream2LLM serving system, organized by workload and configuration.

Structure

run_log/<workload>/<config>/<scheduler>/<timestamp>/
    ├── config_<timestamp>.yaml   # Experiment configuration
    └── run_metrics.csv           # Per-event metrics log

Configurations

Workload	Config Directory	Description
Crawler	H200_enhanced_schedulers_v1_full	Standard H200 runs
Crawler	H200_enhanced_schedulers_v1_full_delay_10	With 10ms artificial delay (memory pressure)
Crawler	H200_..._delay_10_recomp_only	Delay + recomputation-only eviction
Crawler	H200_..._delay_10_swap_only	Delay + swap-only eviction
Crawler	H100_enhanced_schedulers_v1_full	Standard H100 runs
ANNS	H200_enhanced_schedulers_v1_full	Standard H200 runs
ANNS	H200_enhanced_schedulers_v1_500q_delay_30	With 30ms artificial delay (memory pressure)
ANNS	H200_..._delay_30_recomp_only	Delay + recomputation-only eviction
ANNS	H200_..._delay_30_swap_only	Delay + swap-only eviction
ANNS	H100_enhanced_schedulers_v1_full	Standard H100 runs

Schedulers

Each configuration contains results for four scheduling policies:

• default_vllm: Default vLLM scheduler (baseline)
• fcfs: First-come-first-served
• lcas: Last-chunk-arrival-stamp scheduler
• mcps: Most-chunks-processed scheduler

Run Metrics CSV

The run_metrics.csv file logs timestamped events for each experiment run:

Column	Description
event_timestamp	Unix timestamp of the event
event_type	Event type (e.g., replay_start, query_delay, chunk_sent, response_received)
query_id	Query identifier
request_id	vLLM request identifier
stream	Whether streaming input was enabled
concurrency	Whether concurrent requests were enabled
duration_secs	Duration of the event in seconds
details	Additional event-specific information
request_size	Size of the request in tokens
concurrent_requests	Number of concurrent requests at event time
replay_rate	Poisson arrival rate used
prev_event_type	Previous event type for this query

Corpus Content (anns/)

The ANNS corpus is stored as sharded JSON files (retrieved_corpus_content.*.json and retrieved_corpus_content.part.*.json). Each file maps document IDs to their text content, used for constructing input sequences from ANNS retrieval results.

The query_trace_map_5k.json file maps query IDs to their corresponding pipeline trace filenames and query text.