ijuma commented on code in PR #18080: URL: https://github.com/apache/kafka/pull/18080#discussion_r1894810882
########## clients/src/main/java/org/apache/kafka/clients/producer/ProducerConfig.java: ########## @@ -93,8 +93,9 @@ public class ProducerConfig extends AbstractConfig { + "<p>" + "Note: This setting gives the upper bound of the batch size to be sent. If we have fewer than this many bytes accumulated " + "for this partition, we will 'linger' for the <code>linger.ms</code> time waiting for more records to show up. " - + "This <code>linger.ms</code> setting defaults to 0, which means we'll immediately send out a record even the accumulated " - + "batch size is under this <code>batch.size</code> setting."; + + "This <code>linger.ms</code> setting defaults to 5, which means we'll wait 5ms for the accumulated " + + "<code>batch.size</code> to fill as much as it can in this timeframe. This value previously defaulted" + + "to 0, but over time we have observed that the IO overhead caused by smaller batches negates any latency gains."; Review Comment: The wording here is a little odd. I would write something like: "This defaults to 5, which means the producer will wait for 5ms or until the record batch is of <code>batch.size</code> (whichever happens first) before sending the record batch. Note that broker backpressure can result in the effective linger time to be higher than this setting. The default changed from <code>0</code> to <code>5</code> in Apache Kafka 4.0 as the efficiency gains from larger batches typically result in similar or lower producer latency despite the increased linger." -- 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: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org