RedisSeer

A standalone Redis proxy with keepalive and master failover support.

⚠️ This is currently just a proof of concept and it came up from an exercise I wanted to do because I was not able to find a simple Redis proxy/HA that worked for standalone environments that supported both balancing and failover (like how AWS ElastiCache Non-cluster works). I am pretty sure that additional impact in performance will show up when performing benchmarks but if it's something tolerable then I might consider using this in production for non-cluster and non-sentinel environments.

Requirements 📋

• Go if you want to build the project from source (otherwise download one of the releases)

Installation 🚧

# Download from the repository
git clone https://github.com/bvison/redis-seer.git
cd redis-seer
go build

You should see a redis-seer binary inside the folder

Configuration 🛃

redis-seer feeds its configuration from a YAML file that. This is a full sample configuration:

debug: true
port: 5100
selectionMode: "random" # round-robin, random, load
readSlaveOnly: true
enableFailover: true
monitorInterval: 1
db: 0
servers:
  redis1:
    enabled: true
    alias: redis1
    host: "127.0.0.1"
    port: 7000
  redis2:
    enabled: true
    alias: redis2
    host: "127.0.0.1"
    port: 7001
  redis3:
    enabled: true
    alias: redis3
    host: "127.0.0.1"
    port: 7002

As you can see things like database selection and authentication should be configured here and not in the real client.

Some parameters that may need explanation:

• port: Port on which RedisSeer will listen for requests.

• readSlaveOnly: This will avoid sending commands such as GET to the current master.

• enableFailover: Setting this to true will trigger a failover process when the master fails.

• monitorInterval: The interval on which the servers will be contacted for things like: checking the master, pinging the slaves, and also reconnecting when a connection drops.

• db: Database to use when connecting to the redis servers. As of right now if multiple databases are needed additional instances of RedisSeer with different configuration files should be deployed.

• selectionMode: The selection process to be used when picking a server to send the command to.

  • round-robin: Typical round-robin method, the servers will be selected in a sequential way.
  • random (default): A random server will be picked from the list.
  • load: The proxy will keep note on the load sent to the server and will pick the least targeted server.

Usage ▶️

On Linux:

$ ./redis-seer -c config.yml

On Windows:

$ redis-seer.exe -c config.yml

Some flags that can be used:

• -c: Specify the configuration file to use
• -d: Enable additional debugging output

Example 🔌

Inside the tests/redis folder there is a docker-compose.yml file that boots up 3 redis instances to be used with the tests and if you want to you can test redis-seer with them.

Run Redis servers

cd tests/redis
docker-compose up -d

# Run docker ps to confirm that the servers are up and running

Also, inside tests/ there is a config.yml with the sample configuration to be used with this docker-compose.yml. If needed, modify it at will or point the parameter to the correct yml file.

Run RedisSeer

./redis-seer -c tests/config.yml

TODO 🔧

• Ability to disable failover (things like AWS ElastiCache have the SLAVEOF command blocked.)
• Add more configuration options (i.e. authentication)
• Add Makefile
• Add an API
• Docker deployment & Build
• Implement selection method
• Add Master monitoring and failover process
• Add config file as an argument
• Organize code structure
• Make use of channels to improve communication
• Improve error handling
• Handle connection changes more appropriately
• Add tests
• Run benchmarks
• Ansible deployment

Contribution 👷

TBD.