System time is wall-clock time from the Kafka Streams environment. With PunctuationType.WALL_CLOCK_TIME, it drives Punctuator.punctuate at approximately scheduled intervals, regardless of data activity. section 10.2.1 section 10.2.2
Use system-time punctuation when:
- You need activity performed regularly even when records arrive sporadically. section 10.2.2
- You can accept best-effort timing: wall-clock time advances during polling, and execution granularity depends on poll-cycle duration. section 10.2.2
- You want punctuation closer to every ten seconds than data-driven stream-time scheduling provides. section 10.2.2
Scheduling stock-performance checks
A stock-performance processor can schedule a punctuator with context().schedule(10000, PunctuationType.WALL_CLOCK_TIME, punctuator). The check then runs approximately every ten seconds, even when stock transactions are not arriving. section 10.2.1 section 10.2.2
