I agree with John's assessment -- if I'm interpreting it correctly, otherwise I'll claim this idea as my own :P -- that we can just drop it in 3.0 as it was effectively deprecated since day 1, ie version 2.5. In addition to what John said about this not being the default, I'll note that we never directly referenced this config in the upgrade guide, nor do we call out the old vs. new metrics format in the monitoring guide. So for a user to have learned about this new config figure out how to configure Streams to use the old metrics format, I have to assume they did so by reading about it in the KIP <https://cwiki.apache.org/confluence/display/KAFKA/KIP-444%3A+Augment+metrics+for+Kafka+Streams>, which specifically introduces this config as a way "to allow users having a grace period of changing their corresponding monitoring / alerting eco-systems", which seems to make it pretty clear that this was intended as a temporary config that would be removed after this "grace period"
And just to clarify, by "config" above I mostly refer to the specific "0.10.0-2.4" value and not the config itself. I think Guozhang is right that we may want to leverage it again in the future and do not/should not need to remove it now. On Thu, May 20, 2021 at 3:57 PM Guozhang Wang <wangg...@gmail.com> wrote: > I'm also a bit leaning towards dropping the config value in 3.0 directly. > > For the config itself, I'd rather keep it a bit longer in case we may > update the metrics again (there are a couple near term projects on the > roadmap including named topology, restoration threads etc). > > > Guozhang > > On Thu, May 20, 2021 at 8:50 AM John Roesler <vvcep...@apache.org> wrote: > > > Thanks for opening this discussion, Bruno! > > > > I wonder if it would be ok to simply drop that config > > value in 3.0 instead of 4.0. > > > > Config values are a bit different than Java APIs, since many > > users would be using property files or string constants > > instead of referencing the "official" constants defined in > > StreamsConfig.java. As a result, we can expect the > > deprecation warning on the java constant to be only > > marginally effective. > > > > Plus, the config value "latest" has been the default > > already. I don't think it's a stretch for users of the > > "0.10.0-2.4" config value to have seen this coming and to > > have migrated to "latest" already. > > > > If you do agree that we can treat it as having been > > deprecated since 2.5, I'd further suggest that we no longer > > need the "built.in.metrics.version" config at all. > > > > WDYT? > > Thanks, > > John > > > > On Thu, 2021-05-20 at 13:57 +0200, Bruno Cadonna wrote: > > > Hi, > > > > > > I would like to propose KIP-743 to deprecate the old structures of the > > > built-in metrics in Streams. > > > > > > https://cwiki.apache.org/confluence/x/uIfOCg > > > > > > Best, > > > Bruno > > > > > > > > -- > -- Guozhang >
