Firedancer 🔥💃

Firedancer is a new validator client for Solana.

• Fast Designed from the ground up to be fast. The concurrency model is borrowed from the low latency trading space, and the code contains many novel high performance reimplementations of core Solana primitives.
• Secure The architecture of the validator allows it to run with a highly restrictive sandbox and almost no system calls.
• Independent Firedancer is written from scratch. This brings client diversity to the Solana network and helps it stay resilient to supply chain attacks in build tooling or dependencies.

Frankendancer

Firedancer is a new Solana validator with a new codebase, but it is being developed incrementally. To enable testing and deployment before the entire Solana protocol has been implemented we rely on the existing Solana Labs validator code to provide functionality that is missing. This side-by-side configuration is referred to as "frankendancer".

This means building and running a Firedancer validator currently also builds a Solana Labs validator, and runs it as a child process. For now Firedancer has implemented the transaction networking layer, signature verification, deduplication, and packing code. All other functionality, including RPC, transaction execution, remains part of Solana Labs.

Installation

Firedancer is currently under heavy development and is not ready for production use. There are no releases available.

Developing

The below describes building Frankendancer from scratch and running it optimized on a stock Linux image. You will need basic development tools like make, gcc along with rustc, and clang.

Frankendancer currently only supports Linux, and requires a kernel newer than v5.7 to build.

$ sudo dnf groupinstall development
$ curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh

Then you can clone and build the application from source,

$ git clone --recurse-submodules https://github.com/firedancer-io/firedancer.git
$ cd firedancer
$ ./deps.sh
$ make -j run

The make run target runs the fddev dev command. This development command will ensure your system is configured correctly before creating a genesis block, some keys, a faucet, and then starting a validator on the local machine. fddev will use sudo to make privileged changes to system configuration where needed. If sudo is not available, you may need to run the command as root.

By default fddev will create a new development cluster, if you wish to join this cluster with other validators, you can define [rpc.entrypoints] in the configuration file to point at your first validator and run fddev dev again.

Running

In production, it is recommended to configure the system immediately at boot time rather than when running Firedancer. This ensures a contiguous block of memory can be reserved, as it may not be possible when the machine has been running a long time.

$ make -j fdctl
$ ./build/native/gcc/bin/fdctl configure init all

fdctl reads from an optional FIREDANCER_CONFIG_TOML environment variable or --config argument to determine all configuration. A complete list of options and their defaults are provided in default.toml. When providing a configuration file, it only needs to override the options that you wish to change from the default. For example, to set the user gossip port,

user = "firedancer"
[gossip]
  port = 9010

Because Frankendancer relies on the Solana Labs validator for some functionality, most of the options you might need for running Solana Labs are present in the Frankendancer configuration file and will be passed through. RPC commands should continue to work using the existing solana binary, which is built in the solana/target directory as part of make.

Later, when you wish to start the validator, you can run

$ ./build/native/gcc/bin/fdctl run

Unlike fddev, fdctl will not try to gain root to perform configuration, and will not automatically create keys or a genesis. The [rpc.entrypoints] and [consensus.identity_path] configuration options must be defined in order to start the production validator.

Some of the privileged system configuration steps performed by fdctl configure are,

• Huge pages Memory needed for Firedancer must be pre-allocated before launching it. Firedancer uses huge and gigantic memory pages, which are mounted in a local directory. Enabling huge pages and mounting them to a pseudo filesystem requires root privileges.
• XDP Kernel bypass is used for networking, via the eXpress Data Path. Installing the packet filtering code into the kernel requires a privileged process, and must be done before running Firedancer. Firedancer will also set the network driver to use multiple channels to enable receive side scaling, which requires root.
• Kernel parameters Because Frankendancer runs side-by-side with the Solana Labs validator, which requires certain kernel parameters to be tuned (net/core/rmem_max, vm/max_map_count, ...) fdctl will automatically configure these.
• Sandboxing Firedancer installs a BPF program to restrict itself from making certain system calls, and in certain development environemnts fdctl installs network namespaces to simplify network debugging when using XDP. Performing these initial restrictions can require additional capabilities.

A good way to see what privileges are needed to configure the environment is to run fdctl configure init all as a non-privileged user, which will display information about the operations it wishes to perform.

Firedancer must be started as root or with CAP_NET_RAW and CAP_SYS_ADMIN capabilities so that it can initialize XDP in the validator process and bind to a raw socket. Once those steps have been done at startup, Firedancer will drop all privileges, enable a highly restrictive sandbox, and switch to the user provided in the configuration file.

License

Firedancer is available under the Apache 2 license. Firedancer also includes external libraries that are available under a variety of licenses. See LICENSE for the full license text.