Rust::clone(Redis)

⚠️ NOT FOR PRODUCTION USE - toy only ⚠️

This is a clone of Redis.

Features

It supports a tiny subset of the features in real Redis.

The current goal is to support just enough to run the opensource features of Sidekiq.

I have no serious aims to support the full features of real Redis.

Why?

It is for-fun only and not intended to be a "rewrite it in Rust" project 😀.

It exists because I wanted:

• a structured way of getting to know the real Redis source.
• to gain a deeper understanding of how Redis works and why it performs as it does.
• a sufficiently non-trivial project to exercise Rust's async/await and async I/O facilities.

However, my intention is to write fully production quality code, as far as possible. So it might be useful to seed new services that could be driven using Redis-style commands using the RESP protocol.

Dependencies

• Any version of Rust with "Rust 2018 edition" compatibility
  • You can get Rust using https://rustup.rs/
• Redis itself
  • The API/functional tests can be run against real Redis to cross validate
  • We can use redis-cli to connect to and interact with the clone
  • redis-benchmark can be used to compare performance of the clone with the real one
• Ruby 3.* - for the functional test suite

Running

Clone the project then:

cargo run --release

You should see the familiar Redis ASCII art and a comforting message that the clone is listening on port 8080.

[2020-01-17T16:16:44Z WARN  redis_clone] oO0OoO0OoO0Oo Redis Clone is starting oO0OoO0OoO0Oo
[2020-01-17T16:16:44Z WARN  redis_clone] Redis version=0.1.0, bits=64, pid=74915, just started
                _._
           _.-``__ ''-._
      _.-``    `.  `_.  ''-._           Redis Clone 0.1.0 64 bit
  .-`` .-```.  ```\\/    _.,_ ''-._
 (    '      ,       .-`  | `,    )     Running in standalone mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 8080
 |    `-._   `._    /     _.-'    |     PID: 74915
  `-._    `-._  `-./  _.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |     https://github.com/munckymagik/redis-clone
  `-._    `-._`-.__.-'_.-'    _.-'
 |`-._`-._    `-.__.-'    _.-'_.-'|
 |    `-._`-._        _.-'_.-'    |
  `-._    `-._`-.__.-'_.-'    _.-'
      `-._    `-.__.-'    _.-'
          `-._        _.-'
              `-.__.-'

[2020-01-17T16:16:44Z INFO  redis_clone::server] Listening at ("127.0.0.1", 8080)

Using

You can use the redis-cli command to connect to the clone:

redis-cli -p 8080

Then you can see what commands are available:

127.0.0.1:8080> COMMAND
 1) 1) "get"
    2) (integer) 2
 2) 1) "set"
    2) (integer) -3
# ... snip ...
 23) 1) "keys"
    2) (integer) 2

Testing

There are two kinds of tests:

• Unit tests within the Rust source code
• A suite of functional tests that use Ruby and the Ruby Redis Gem to test the supported commands

To run the Rust tests for all packages in the workspace:

cargo test

The for the functional tests:

cd tests/functional
bundle install
./bin/rspec

To run the test suite against real Redis do this:

TEST_REAL_REDIS=1 bundle exec rspec

Benchmarking

The redis-benchmark tool can be used, but make sure to

1. only specify tests for commands the clone supports
2. specify port 8080

redis-benchmark -p 8080 -t SET,GET,INCR

A script that runs the supported tests against both real Redis the clone is available in:

./benches/clone-vs-real.sh

Development

Use the scripts under the ./scripts folder to watch, build and re-run the tests.

They depend on cargo-watch so make sure to install it first with cargo install cargo-watch. Then

1. In one terminal watch and rebuild the server:

   ./scripts/watch-server

2. In another terminal watch the server and re-run the tests. This also runs the tests against "real" Redis so make sure that's running too:

   ./scripts/watch-feature-tests