LingerMs default is 0 or 5?

[NickLydon]

Description

The comment for ProducerConfig.LingerMs says that the default is 5, whereas the confluent docs say it's 0. Is this a typo or does the dotnet client actually supply different defaults?

[mhowlett]

those docs are for the java client.

in librdkafka (and the dotnet client), the default is 5ms. https://github.com/edenhill/librdkafka/blob/master/src/rdkafka_conf.c#L1326

5ms is a better general purpose default setting which is good for a very wide range of scenarios. you would only want 0ms for low throughput applications where latency is critical (you will get better latency in higher throughput scenarios with a non-zero linger.ms).

[NickLydon]

Thanks for the reply. If we're using ProduceAsync (albeit with concurrent calls to it) are we also getting the benefit of LingerMs? Or would we have to use Produce?

[mhowlett]

ProduceAsync and Produce are both thin layers on top of the same librdkafka capability. Applies to both.