BurstGPT Load Generator Converter

A tool to convert CSV files containing ChatGPT/GPT-4 conversation logs into mooncake-style JSONL format for load testing and simulation.

Note

Currently, KV reuse is not considered in the output. We will update the script once BurstGPT adds user session information.

Input Format

The input CSV can be downloaded from BurstGPT Release v1.1:

• Timestamp: Request timestamp in seconds
• Model: Model name (e.g., "ChatGPT", "GPT-4")
• Request tokens: Number of input tokens
• Response tokens: Number of output tokens
• Total tokens: Total tokens (not used)
• Log Type: Type of log (e.g., "Conversation log", "API log")

Example:

Timestamp,Model,Request tokens,Response tokens,Total tokens,Log Type
5,ChatGPT,472,18,490,Conversation log
45,ChatGPT,1087,230,1317,Conversation log
118,GPT-4,417,276,693,Conversation log

Output Format

The output is a JSONL file where each line is a JSON object:

{"timestamp": 5000, "input_length": 472, "output_length": 18, "hash_ids": [123, 456, 789, ...]}

Fields:

• timestamp: Request time in milliseconds (integer)
• input_length: Number of input tokens
• output_length: Number of output tokens
• hash_ids: Array of random hash IDs simulating KV cache blocks

Usage

Basic Usage

python convert.py --input-file <BurstGPT CSV data>

If --output-file is not specified, the output will use the input filename with .jsonl extension.

Command Line Arguments

Required Arguments

• --input-file: Path to the input CSV file

Optional Arguments

Filtering:

• --model: Filter by model (ChatGPT or GPT-4), None for no filtering
• --log-type: Filter by log type (Conversation log or API log), None for no filtering
• --num-prompt: Limit number of rows in the final output, None for no filtering

Timestamp Adjustment:

• --speed-ratio: Adjust request timing (default: 1.0)
  • Values > 1: Speed up (e.g., 2.0 = 2x faster)
  • Values < 1: Slow down (e.g., 0.5 = 2x slower)
  • Formula: new_timestamp = old_timestamp / speed_ratio

Hash Generation:

• --block-size: Block size in mooncake traces (default: 128)
• --num-hash-blocks: Maximum hash ID value (default: 10000). Hash IDs are randomly chosen from 0 to this value for each block. Output:
• --output-file: Path to output JSONL file (default: input filename with .jsonl extension)

Statistics Output

After conversion, the script displays statistics about the generated workload:

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STATISTICS
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Input Length (ISL):
  Min: 37
  Max: 1528
  Avg: 705.89
  Std: 524.33

Output Length (OSL):
  Min: 18
  Max: 1656
  Avg: 494.67
  Std: 513.21

Sequence Length (ISL + OSL):
  Max: 3184

Request Rate:
  Total requests: 9
  Duration: 405.00 seconds
  Average RPS: 0.02
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