Steadybit extension-redis

A Steadybit extension for Redis chaos engineering.

Learn about the capabilities of this extension in our Reliability Hub.

Configuration

Environment Variable	Required	Description
STEADYBIT_EXTENSION_ENDPOINTS_JSON	Yes	JSON array of Redis endpoint configurations
STEADYBIT_EXTENSION_DISCOVERY_INTERVAL_INSTANCE_SECONDS	No	Interval for instance discovery (default: 30)
STEADYBIT_EXTENSION_DISCOVERY_INTERVAL_DATABASE_SECONDS	No	Interval for database discovery (default: 60)

Endpoint Configuration

The STEADYBIT_EXTENSION_ENDPOINTS_JSON environment variable should contain a JSON array of Redis endpoint configurations:

[
  {
    "url": "redis://localhost:6379",
    "password": "optional-password",
    "username": "optional-username",
    "db": 0,
    "name": "my-redis-instance",
    "insecureSkipVerify": false
  }
]

TLS Configuration

For TLS connections, use the rediss:// URL scheme:

[
  {
    "url": "rediss://redis.example.com:6379",
    "password": "secret",
    "insecureSkipVerify": true
  }
]

Supported Targets

Redis Instance

Discovers Redis instances and exposes attributes like:

• redis.host - Redis host
• redis.port - Redis port
• redis.version - Redis version
• redis.role - Instance role (master/replica)
• redis.cluster.enabled - Cluster mode status

Redis Database

Discovers Redis databases (db0-db15) and exposes:

• redis.database.index - Database index
• redis.database.keys - Key count in database
• redis.database.name - Database name (e.g., "db0")

Supported Actions

Attacks

Exhaust Connections

• ID: com.steadybit.extension_redis.instance.connection-exhaustion
• Target: Instance
• Description: Opens many connections to test connection limit handling
• Parameters:
  • duration - How long to hold connections
  • numConnections - Number of connections to open (default: 100)

Pause Clients

• ID: com.steadybit.extension_redis.instance.client-pause
• Target: Instance
• Description: Suspends all client command processing using CLIENT PAUSE
• Parameters:
  • duration - How long to pause clients
  • pauseMode - ALL (all commands) or WRITE (write commands only)
• Reversibility: Auto-reverts after timeout

Limit MaxMemory

• ID: com.steadybit.extension_redis.instance.maxmemory-limit
• Target: Instance
• Description: Reduces Redis maxmemory to force evictions or OOM errors
• Parameters:
  • duration - How long to apply the limit
  • maxmemory - Memory limit (e.g., "10mb", "1gb")
  • evictionPolicy - noeviction, allkeys-lru, allkeys-lfu, volatile-lru, volatile-ttl, or keep original
• Reversibility: Fully reversible - restores original settings on stop

Force Cache Expiration

• ID: com.steadybit.extension_redis.database.cache-expiration
• Target: Database
• Description: Sets TTL on string keys matching a pattern to force expiration (non-string keys are skipped)
• Parameters:
  • duration - Attack duration (for tracking)
  • pattern - Key pattern to match (only string keys are affected)
  • ttl - TTL in seconds before keys expire (default: 5)
  • maxKeys - Maximum keys to affect (default: 100)
  • restoreOnStop - Restore keys with original values and TTLs when attack stops (default: false)
• Reversibility: Reversible when restoreOnStop is enabled - recreates expired keys with original values and TTLs

Stop Sentinel

• ID: com.steadybit.extension_redis.instance.sentinel-stop
• Target: Instance
• Description: Stops a Redis Sentinel server using DEBUG SLEEP, making it unresponsive to all clients and other Sentinels
• Parameters:
  • duration - How long the Sentinel should be unresponsive (default: 30s)
• Reversibility: Auto-recovers after the sleep duration

Checks

Memory Usage Check

• ID: com.steadybit.extension_redis.instance.check-memory
• Target: Instance
• Description: Monitors Redis memory usage and fails if threshold exceeded
• Parameters:
  • duration - Monitoring duration
  • maxMemoryPercent - Max memory as % of maxmemory (default: 80%)
  • maxMemoryBytes - Max memory in MB (optional)

Latency Check

• ID: com.steadybit.extension_redis.instance.check-latency
• Target: Instance
• Description: Monitors Redis response latency
• Parameters:
  • duration - Monitoring duration
  • maxLatencyMs - Maximum allowed latency in ms (default: 100)

Connection Count Check

• ID: com.steadybit.extension_redis.instance.check-connections
• Target: Instance
• Description: Monitors connected clients and fails if threshold exceeded
• Parameters:
  • duration - Monitoring duration
  • maxConnectionsPct - Max connections as % of maxclients (default: 80%)
  • maxConnections - Absolute max connections (optional)

Replication Lag Check

• ID: com.steadybit.extension_redis.instance.check-replication
• Target: Instance
• Description: Monitors Redis replication status and lag for replicas
• Parameters:
  • duration - Monitoring duration
  • maxLagSeconds - Maximum allowed replication lag (default: 10s)
  • requireLinkUp - Fail if master link is down (default: true)

Demo Environment & Chaos Experiments

A complete demo environment with a sample application and chaos engineering experiments is available in the demo/ directory.

Quick Start

cd demo
docker-compose up -d

This starts:

• redis-master: Primary Redis (port 6379)
• redis-replica: Replica for HA testing (port 6380)
• demo-app: Sample app with caching (port 3400)
• load-generator: Continuous traffic generator

Chaos Experiments

See demo/CHAOS_EXPERIMENTS.md for detailed chaos engineering scenarios including:

User-Facing Scenarios:

• Cache unavailability impact
• Session loss handling
• Slow cache response
• Cache stampede (thundering herd)

SRE/Platform Scenarios:

• Connection pool exhaustion
• Memory pressure & eviction
• Replication lag
• Redis failover

Installation

Helm

helm repo add steadybit https://steadybit.github.io/helm-charts
helm repo update
helm install steadybit-extension-redis steadybit/steadybit-extension-redis \
  --set redis.auth.managementEndpoints='[{"url":"redis://redis:6379"}]'

Docker

docker run -d \
  -e STEADYBIT_EXTENSION_ENDPOINTS_JSON='[{"url":"redis://redis:6379"}]' \
  -p 8083:8083 \
  ghcr.io/steadybit/extension-redis:latest

Development

Prerequisites

• Go 1.25+
• Redis instance for testing
• Docker (for demo environment)

Build

make build

Test

# Unit tests only
go test ./clients/... ./config/... ./extredis/... -v

# All tests including e2e (requires minikube)
make test

Run locally

# Start Redis
./scripts/start-redis.sh

# Run extension
export STEADYBIT_EXTENSION_ENDPOINTS_JSON='[{"url":"redis://localhost:6379","password":"dev-password"}]'
make run

License

MIT License - see LICENSE for details.