scylladb

# Scylla

[![Slack](https://img.shields.io/badge/slack-scylla-brightgreen.svg?logo=slack)](http://slack.scylladb.com)
[![Twitter](https://img.shields.io/twitter/follow/ScyllaDB.svg?style=social&label=Follow)](https://twitter.com/intent/follow?screen_name=ScyllaDB)

## What is Scylla?

Scylla is the real-time big data database that is API-compatible with Apache Cassandra and Amazon DynamoDB.
Scylla embraces a shared-nothing approach that increases throughput and storage capacity to realize order-of-magnitude performance improvements and reduce hardware costs.

For more information, please see the [ScyllaDB web site].

[ScyllaDB web site]: https://www.scylladb.com

## Build Prerequisites

Scylla is fairly fussy about its build environment, requiring very recent
versions of the C++23 compiler and of many libraries to build. The document
[HACKING.md](HACKING.md) includes detailed information on building and
developing Scylla, but to get Scylla building quickly on (almost) any build
machine, Scylla offers a [frozen toolchain](tools/toolchain/README.md).
This is a pre-configured Docker image which includes recent versions of all
the required compilers, libraries and build tools. Using the frozen toolchain
allows you to avoid changing anything in your build machine to meet Scylla's
requirements - you just need to meet the frozen toolchain's prerequisites
(mostly, Docker or Podman being available).

## Building Scylla

Building Scylla with the frozen toolchain `dbuild` is as easy as:

```bash
$ git submodule update --init --force --recursive
$ ./tools/toolchain/dbuild ./configure.py
$ ./tools/toolchain/dbuild ninja build/release/scylla
```

For further information, please see:

* [Developer documentation] for more information on building Scylla.
* [Build documentation] on how to build Scylla binaries, tests, and packages.
* [Docker image build documentation] for information on how to build Docker images.

[developer documentation]: HACKING.md
[build documentation]: docs/dev/building.md
[docker image build documentation]: dist/docker/redhat/README.md

## Running Scylla

To start Scylla server, run:

```bash
$ ./tools/toolchain/dbuild ./build/release/scylla --workdir tmp --smp 1 --developer-mode 1
```

This will start a Scylla node with one CPU core allocated to it and data files stored in the `tmp` directory.
The `--developer-mode` is needed to disable the various checks Scylla performs at startup to ensure the machine is configured for maximum performance (not relevant on development workstations).
Please note that you need to run Scylla with `dbuild` if you built it with the frozen toolchain.

For more run options, run:

```bash
$ ./tools/toolchain/dbuild ./build/release/scylla --help
```

## Testing

[![Check Reproducible Build](https://github.com/scylladb/scylladb/actions/workflows/reproducible-build.yaml/badge.svg)](https://github.com/scylladb/scylladb/actions/workflows/reproducible-build.yaml) [![clang-nightly](https://github.com/scylladb/scylladb/a