Did a test with one gateway and collected 250000 😲 value changes per second(!) from 10 OPC UA servers and wrote it to 10 topics on a single Kafka Broker… Kafka was bored 😴… one and a half core of an i7 PC. The gateway had a lot of work to do, collect and bulk all the single values and then send it to Kafka … roughly 10 cores of an i7 PC.
The gateway has a GraphQL and MQTT interface where you can read and write OPC UA values. On an internal MQTT topic the logger publishes how many values are getting in and out…