Coincidentally, someone else in the ASF slack mentioned [1] yesterday that they were seeing significantly reduced performance using KafkaIO.Read w/ the SDF wrapper vs the unbounded source. They mentioned they were using flink 1.9.
https://the-asf.slack.com/archives/C9H0YNP3P/p1607057900393900 On Thu, Dec 3, 2020 at 1:56 PM Boyuan Zhang <boyu...@google.com> wrote: > Hi Steve, > > I think the major performance regression comes from > OutputAndTimeBoundedSplittableProcessElementInvoker[1], which will > checkpoint the DoFn based on time/output limit and use timers/state to > reschedule works. > > [1] > https://github.com/apache/beam/blob/master/runners/core-java/src/main/java/org/apache/beam/runners/core/OutputAndTimeBoundedSplittableProcessElementInvoker.java > > On Thu, Dec 3, 2020 at 9:40 AM Steve Niemitz <sniem...@apache.org> wrote: > >> I have a pipeline that reads from pubsub, does some aggregation, and >> writes to various places. Previously, in older versions of beam, when >> running this in the DirectRunner, messages would go through the pipeline >> almost instantly, making it very easy to debug locally, etc. >> >> However, after upgrading to beam 2.25, I noticed that it could take on >> the order of 5-10 minutes for messages to get from the pubsub read step to >> the next step in the pipeline (deserializing them, etc). The subscription >> being read from has on the order of 100,000 elements/sec arriving in it. >> >> Setting --experiments=use_deprecated_read fixes it, and makes the >> pipeline behave as it did before. >> >> It seems like the SDF implementation in the DirectRunner here is causing >> some kind of issue, either buffering a very large amount of data before >> emitting it in a bundle, or something else. Has anyone else run into this? >> >
