jargon

Data engineering·Time and correctness in streams

you restarted the job to fix a bug and every bucket moved, because the buckets were made from when the job read the record.

Processing time

Also calledwall-clock time, arrival time

The clock on the machine doing the work, at the moment it handles the record. It is always available, always in order and never late, which makes it a tempting default and makes every result computed on it irreproducible. Use it for operational questions about the pipeline itself — throughput, lag, how busy a consumer is — and never for a number a person will compare week to week.

Commonly confused with