tvalentyn commented on code in PR #31969: URL: https://github.com/apache/beam/pull/31969#discussion_r1695724254
########## sdks/python/apache_beam/metrics/cells.py: ########## @@ -553,3 +610,22 @@ def combine(self, x, y): def result(self, x): # type: (GaugeData) -> GaugeResult return GaugeResult(x.get_cumulative()) + + +class StringSetAggregator(MetricAggregator): + @staticmethod + def identity_element(): + # type: () -> set + return set() + + def combine(self, x, y): + # type: (set, set) -> set + if len(x) == 0: + return y + elif len(y) == 0: + return x + else: + return set.union(x, y) Review Comment: I think it depends on the lifecycle of these sets; given Java implementation, my guess is that it is probably not a concern. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@beam.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org