Contender

Contender is a high-performance Ethereum network spammer and testing tool designed for benchmarking and stress-testing Ethereum clients and networks.

Features

• Flexible Transaction Generation: Create custom transaction patterns using TOML configuration files.
• Multiple Spamming Modes: Support for both timed and block-wise spamming.
• Seed-based Randomization: Reproducible fuzzing with customizable seed values.
• Database Integration: SQLite backend to store contract/transaction data and analyze test results.
• Extensible Architecture: Easy-to-implement custom generators and callbacks.

Installation

To install the Contender CLI, you need to have the Rust toolchain and libsqlite3-dev installed on your system. Then install from github:

cargo install --git https://github.com/flashbots/contender --bin contender

Usage

Contender can be used as both a library and a command-line tool.

Command-line Interface

contender setup <testfile> <rpc_url> [OPTIONS]
contender spam <testfile> <rpc_url> [OPTIONS]
contender report [OPTIONS]

For detailed usage instructions, run:

contender --help

Library Usage

To use Contender as a library in your Rust project, add the crates you need to your Cargo.toml:

[dependencies]
...
contender_core = { git = "https://github.com/flashbots/contender" }
contender_sqlite = { git = "https://github.com/flashbots/contender" }
contender_testfile = { git = "https://github.com/flashbots/contender" }
# not necessarily required, but recommended:
tokio = { version = "1.40.0", features = ["rt-multi-thread"] }

use contender_core::{
    db::DbOps,
    generator::RandSeed,
    spammer::{BlockwiseSpammer, TimedSpammer, NilCallback, LogCallback},
    test_scenario::TestScenario,
};
use contender_sqlite::SqliteDb;
use contender_testfile::TestConfig;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let db = &SqliteDb::new_memory();
    db.create_tables()?;
    let cfg = TestConfig::from_file("testfile.toml")?;
    let mut agents = AgentStore::new();
    let rand_seed = RandSeed::new();
    agents.add_random_agent(
        "agentName",
        4, // number of random signers to create
        rand_seed
    )
    let scenario = TestScenario::new(
        cfg,
        db.to_owned().into(),
        "http://localhost:8545".parse::<_>()?,
        None,
        rand_seed,
        &[
            "0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80",
            "0x59c6995e998f97a5a0044966f0945389dc9e86dae88c7a8412f4603b6b78690d",
            "0x5de4111afa1a4b94908f83103eb1f1706367c2e68ca870fc3fb9a804cdab365a",
        ]
        .iter()
        .map(|s| s.parse::<_>().unwrap())
        .collect::<Vec<_>>(),
        agents
    );

    if db.get_named_tx("MyContract").is_err() {
        scenario.deploy_contracts().await?;
        scenario.run_setup().await?;
    }

    let spammer = TimedSpammer::new(std::time::Duration::from_secs(1));
    // or
    // let spammer = BlockwiseSpammer {};

    // callback is triggered when tx/bundle request is sent
    // NilCallback does nothing, LogCallback writes tx data to DB
    let tx_callback = LogCallback::new(scenario.rpc_client().clone());
    // or
    // let tx_callback = NilCallback;

    // placeholder; this should identify the run in the DB
    let run_id = 1_u64;
    
    // send 20 requests per second, over 10 seconds
    spammer.spam_rpc(&mut scenario, 20, 10, Some(run_id), tx_callback.into()).await?;

    Ok(())
}

Configuration

Contender uses TOML files for test configuration. Single brackets [] indicate the item may only be specified once. Double brackets [[]] indicate an array, which allows the directive to be specified multiple times.

The key directives are:

• [env]: Defines environment variables that can be used throughout the configuration.

• [[create]]: Specifies contracts to be deployed. Each entry represents a contract creation.

• [[setup]]: Defines setup transactions to be executed before the main spam test. These are typically used for initializing contracts or setting up test conditions.

• [[spam]]: Describes the transactions to be repeatedly sent during the spam test. These form the core of the network stress test.

  • Spam directives can send bundles or single txs.

  • [[spam.bundle.tx]] defines transactions in a bundle

  • [spam.tx] defines a single transaction

  • Each tx directive can include various fields such as to, from, signature, args, and value to specify the details of the transactions or contract interactions.

  • [[spam.bundle.tx.fuzz]] or [[spam.tx.fuzz]]: Configures fuzzing parameters for specific fields in spam transactions, allowing for randomized inputs or ETH values within defined ranges.

See scenarios/ for examples.

Architecture

Contender is built with a modular architecture:

• Generators: Produce transaction requests based on configuration.
• Spammers: Send transactions to the network at specified rates.
• Callbacks: Handle post-transaction actions and logging.
• Database: Store and retrieve test results and contract addresses.

graph TD
    A[TOML Config File] -->|Parsed by| B[TestConfig]
    B -->|Configures| C[Generator]
    C -->|Produces| D[Transaction Requests]
    D -->|Fed to| E[Spammer]
    E -->|Sends txs| F[Ethereum Network]
    F -->|Responses| G[Callback Handler]
    G -->|Logs results| H[Database]
    
    I[CLI] -->|Reads| A
    I -->|Controls| E
    I -->|Queries| H
    
    H -->|Data for| J[Report Generator]

    %% Component descriptions
    A:::config
    B:::config
    C:::core
    D:::core
    E:::core
    F:::external
    G:::core
    H:::storage
    I:::interface
    J:::analysis

    classDef config fill:#f9f,stroke:#333,stroke-width:2px;
    classDef core fill:#bbf,stroke:#333,stroke-width:2px;
    classDef external fill:#bfb,stroke:#333,stroke-width:2px;
    classDef storage fill:#fbb,stroke:#333,stroke-width:2px;
    classDef interface fill:#bff,stroke:#333,stroke-width:2px;
    classDef analysis fill:#ffb,stroke:#333,stroke-width:2px;

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Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgements

• The Ethereum community for their continuous innovation.
• The Reth project for inspiration on project structure and documentation.
• alloy-rs -- the backbone of this project.