Open Source4 min read
Stream processing · FLIP-21
Apache Flink wants to stop copying data at every operator. That's the easy part
FLIP-21 would let Apache Flink stop copying data between every chained operator, replacing a long-standing safety default with three selectable modes. DEFAULT, COPY_PER_OPERATOR, and FULL_REUSE split the difference between speed and caution. The migration question is still open.
2026-09-14