Redis

Redis is an in-memory data structure store that serves multiple roles in industrial architectures: high-speed cache, message broker, stream processor, and lightweight database. For manufacturing and Industry 4.0 applications, Redis Streams provides a purpose-built solution for event sourcing and real-time data pipelines.

Redis Streams for manufacturing

Redis Streams is a log data structure that models an append-only sequence of events. Unlike traditional message queues, Streams preserve history and support multiple consumers with different speeds and processing guarantees.

Key features:

• Event IDs: Millisecond-precision timestamps with sequence numbers (e.g., 1526919030474-55)
• Consumer Groups: Multiple consumers process the same stream with automatic load balancing
• Pending Entries: Track messages that were delivered but not acknowledged
• Range Queries: Read historical data by time range or message ID
• Blocking Reads: Wait for new messages with configurable timeouts

Architecture patterns

Edge buffering

Deploy Redis at the edge to buffer sensor data during network outages. Streams automatically handle backpressure and allow replay when connectivity returns.

Sensor → Redis Stream → (network restored) → Cloud/ERP

Event sourcing

Use Streams as the system of record for machine events. Each state change (start, stop, alarm, parameter update) becomes an immutable event in the stream.

Command distribution

Publish commands to control systems using Redis Pub/Sub or Streams. Guaranteed delivery via consumer groups ensures critical commands are processed exactly once.

Deployment options

• Single Instance: Simplest setup, suitable for edge devices and small deployments
• Sentinel: High availability with automatic failover
• Cluster: Horizontal scaling across multiple nodes for high-throughput scenarios
• Redis Stack: Includes RedisJSON, RediSearch, RedisTimeSeries, and RedisGraph modules

Limitations

• All data must fit in memory (though Redis supports eviction policies)
• Single-threaded command execution (horizontal scaling via Cluster mode)
• No built-in MQTT protocol support (requires bridge or adapter)
• Enterprise features (Redis Enterprise) require commercial license

Integration ecosystem

Redis integrates with major industrial platforms through:

• Node-RED: node-red-contrib-redis nodes for flow-based integration
• Apache Kafka: Kafka Connect Redis sink/source connectors
• Telegraf: Redis input plugin for metrics collection
• Grafana: Redis Data Source for dashboards and alerting