Same. There is a backward compatibility risk (we are changing the behavior, and the assessment that it won't affect anyone may be correct - but there is a risk that people depend on existing behaviors in ways we didn't consider)
Remember that users are yelling on twitter even when we do small and very reasonable changes: https://twitter.com/jessetanderson/status/1250095104779378690 Since we want to encourage users to move to a significantly better and safer alternative, I just don't see how the compatibility risk is justified. Gwen On Fri, May 8, 2020 at 4:08 PM Matthias J. Sax <[email protected]> wrote: > With the discussion about a 3.0 release and deprecating the old MM, I am > wondering if it's worth to do anything. > > Please should just switch to MM2 that has a better default. > > Thoughts? > > > On 4/27/20 10:48 AM, Ryanne Dolan wrote: > > Conversely, we could consider making MM2 use "latest" in "legacy mode", > and > > leave MM1 as it is? (Just thinking out loud.) > > > > Ryanne > > > > On Mon, Apr 27, 2020 at 12:39 PM Jeff Widman <[email protected]> > wrote: > > > >> Good questions: > >> > >> > >> *I agree that `auto.offset.reset="earliest"` would be a better default. > >> However, I am a little worried about backwardcompatibility. * > >> > >> Keep in mind that existing mirrormaker instances will *not* be affected > for > >> topics they are currently consuming because they will already have saved > >> offsets. This will only affect mirrormakers that start consuming new > >> topics, for which they don't have a saved offset. In those cases, they > will > >> stop seeing data loss when they first start consuming. My guess is the > >> majority of those new topics are going to be newly-created topics > anyway, > >> so most of the time starting from the earliest simply prevents skipping > the > >> first few seconds/minutes of data written to the topic. > >> > >> *What I am also wondering thought is, does this only affect MirrorMaker > or > >> also MirrorMaker 2? * > >> > >> I checked and MM2 already sets `auto.offset.reset = 'earliest'` > >> < > >> > https://github.com/apache/kafka/blob/d63eaaaa0181bb7b9b4f5ed088abc00d7b32aeb0/connect/mirror/src/main/java/org/apache/kafka/connect/mirror/MirrorConnectorConfig.java#L233 > >>> > >> . > >> > >> *Also, is it worth to change MirrorMaker now that **MirrorMaker 2 is > >> available?* > >> > >> Given that it's 1-line of code, doesn't affect existing instances, and > >> prevents data loss on new regex subscriptions, I think it's worth > >> setting... I basically view it as a bugfix rather than a feature change. > >> > >> I realize MM1 is deprecated, but there's still a lot of old mirrormakers > >> running, so flipping this now will ease the future transition to MM2 > >> because it brings the behavior of MM1 in line with MM2. > >> > >> Thoughts? > >> > >> > >> > >> On Sat, Apr 11, 2020 at 11:59 AM Matthias J. Sax <[email protected]> > wrote: > >> > >>> Jeff, > >>> > >>> thanks for the KIP. I agree that `auto.offset.reset="earliest"` would > be > >>> a better default. However, I am a little worried about backward > >>> compatibility. And even if the current default is not idea, users can > >>> still change it. > >>> > >>> What I am also wondering thought is, does this only affect MirrorMaker > >>> or also MirrorMaker 2? Also, is it worth to change MirrorMaker now that > >>> MirrorMaker 2 is available? > >>> > >>> > >>> -Matthias > >>> > >>> > >>> On 4/10/20 9:56 PM, Jeff Widman wrote: > >>>> > >>> > >> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-592%3A+MirrorMaker+should+replicate+topics+from+earliest > >>>> > >>>> It's a relatively minor change, only one line of code. :-D > >>>> > >>>> > >>>> > >>> > >>> > >> > >> -- > >> > >> *Jeff Widman* > >> jeffwidman.com <http://www.jeffwidman.com/> | 740-WIDMAN-J (943-6265) > >> <>< > >> > > > > -- Gwen Shapira Engineering Manager | Confluent 650.450.2760 | @gwenshap Follow us: Twitter | blog
