Hi Mario, I think the idea with "ConnectorPlugin" is that it only applies to plugins that are used directly by connectors, which excludes worker-level plugins like the connector client override policy and REST extension interfaces. So IMO we should pick one of these two mutually-exclusive options:
1. Name the parent interface "ConnectorPlugin" and only use it for connector plugins but not worker plugins* 2. Name the parent interface something else (maybe just "ConnectPlugin"?) and use it for both connector and worker plugins * - Note that this doesn't preclude us from adding a config() method to the worker plugin interfaces, just from using the same parent interface name as the one for connector plugins I'd lean towards the second option but I'd accept either. I suspect Mickael would prefer the first but will let him weigh in :) Cheers, Chris On Fri, Feb 6, 2026 at 5:54 AM Mario Fiore Vitale via dev < [email protected]> wrote: > Hi Everyone, > > I have updated the KIP document with the ConnectorPlugin. I'll appreciate > any feedback. > > Thanks, > Mario. > > Il giorno ven 6 feb 2026 alle ore 09:37 Mario Fiore Vitale < > [email protected]> ha scritto: > > > Hi Mickael, > > > > I got it. So I'll update the KIP with the ConnectorPlugin interface > having > > version() and config() methods. > > > > Thanks, > > Mario > > > > Il giorno gio 5 feb 2026 alle ore 18:24 Mickael Maison < > > [email protected]> ha scritto: > > > >> Hi, > >> > >> Connectors, transformations, predicates are typically referred as > >> "connector plugins". > >> On the other hand ConnectRestExtension, > >> ConnectorClientConfigOverridePolicy and ConfigProvider are "worker > >> plugins". > >> Yes it's confusing! The terms connectors and plugins are really > overused. > >> > >> Mickael > >> > >> On Thu, Feb 5, 2026 at 5:58 PM Mario Fiore Vitale via dev > >> <[email protected]> wrote: > >> > > >> > > Otherwise we could have a ConnectorPlugin interface (putting aside > the > >> > worker plugins for now as they don't have a config() method) bringing > >> > config() and version() that all plugins interface would implement? > >> > > >> > So If I get it correctly, you are proposing to have a single interface > >> > (ConnectorPlugin) that replaces the Versioned and the > >> > ConfigSpecifier, merging them. > >> > Sounds reasonable. In that case, I'll use a more generic name like > >> > *ConnectPlugin > >> > *since it will be used not only for connectors but also for > >> transformation, > >> > predicates, and converters. > >> > > >> > Mickael, Chris, WDYT? > >> > > >> > > I like the ConnectorPlugin interface idea. Mario, would that suit > >> your use > >> > case? > >> > > >> > The result is the same, so it is good. > >> > > >> > Thanks, > >> > Mario. > >> > > >> > Il giorno gio 5 feb 2026 alle ore 16:53 Chris Egerton < > >> > [email protected]> ha scritto: > >> > > >> > > I agree that ConfigSpecifier is a little clunky, but IMO Configured > >> is a > >> > > little too be similar to the existing Configurable interface. > >> > > > >> > > I like the ConnectorPlugin interface idea. Mario, would that suit > >> your use > >> > > case? > >> > > > >> > > On Thu, Feb 5, 2026, 10:24 Mickael Maison <[email protected] > > > >> > > wrote: > >> > > > >> > > > Hi Mario, > >> > > > > >> > > > Thanks for the KIP. > >> > > > > >> > > > Today the mechanism to discover plugins and their configurations > is > >> > > > the REST API. > >> > > > You can retrieve the list of all installed connectors plugins > >> > > > (connectors, transformations, predicates) via GET > >> > > > /connector-plugins?connectorsOnly=false > >> > > > You can get their configurations via GET > >> > > /connector-plugins/{plugin}/config > >> > > > > >> > > > That said, I'm not against bringing consistency to the plugin > APIs, > >> > > > especially as the drawbacks are really minor. > >> > > > In terms of naming I'm not a huge fan of ConfigSpecifier. I don't > >> have > >> > > > a great alternative to suggest. > >> > > > To follow the naming of Versioned, maybe we can consider > Configured? > >> > > > Otherwise we could have a ConnectorPlugin interface (putting aside > >> the > >> > > > worker plugins for now as they don't have a config() method) > >> bringing > >> > > > config() and version() that all plugins interface would implement? > >> > > > > >> > > > Thanks, > >> > > > Mickael > >> > > > > >> > > > > >> > > > On Mon, Feb 2, 2026 at 9:48 AM Mario Fiore Vitale via dev > >> > > > <[email protected]> wrote: > >> > > > > > >> > > > > Hi Everyone, > >> > > > > > >> > > > > Just a ping to bring the discussion up. > >> > > > > > >> > > > > Thanks, > >> > > > > Mario. > >> > > > > > >> > > > > Il giorno mar 27 gen 2026 alle ore 09:17 Mario Fiore Vitale < > >> > > > > [email protected]> ha scritto: > >> > > > > > >> > > > > > Hi Chris, > >> > > > > > > >> > > > > > Thanks for the feedback. I updated the wrong Javadoc. > >> > > > > > > >> > > > > > Any other comments from anybody? > >> > > > > > > >> > > > > > Thanks, > >> > > > > > Mario. > >> > > > > > > >> > > > > > Il giorno ven 23 gen 2026 alle ore 07:31 Chris Egerton < > >> > > > > > [email protected]> ha scritto: > >> > > > > > > >> > > > > >> Hi Mario, > >> > > > > >> > >> > > > > >> Thanks for the updates, especially the comprehensive > >> compatibility > >> > > > > >> section! > >> > > > > >> The KIP looks good to me, though you may want to double-check > >> the > >> > > > example > >> > > > > >> Javadocs on ConnectRestExtension::config > >> > > > > >> and ConnectorClientConfigOverridePolicy::config :) > >> > > > > >> > >> > > > > >> Cheers, > >> > > > > >> > >> > > > > >> Chris > >> > > > > >> > >> > > > > >> On Thu, Jan 22, 2026 at 5:54 AM Mario Fiore Vitale via dev < > >> > > > > >> [email protected]> wrote: > >> > > > > >> > >> > > > > >> > Hi Chris, thanks for your valuable feedback! > >> > > > > >> > > >> > > > > >> > > 1. (Minor) The Javadoc for HeaderConverter::config is a > >> little > >> > > > > >> > strange--is > >> > > > > >> > it meant to refer to "this set of header converters" or > >> should it > >> > > > just > >> > > > > >> be > >> > > > > >> > "this header converter"? > >> > > > > >> > > >> > > > > >> > This was just taken from the current source. But I agree > >> that it > >> > > > should > >> > > > > >> be > >> > > > > >> > "this header converter". > >> > > > > >> > > >> > > > > >> > > For example, there's the obvious case > >> > > > > >> > where a plugin instantiates an object with a left-hand-type > >> of > >> > > > > >> > ConfigSpecifier in its constructor. That plugin would be > >> > > > incompatible > >> > > > > >> with > >> > > > > >> > older versions of Connect. > >> > > > > >> > > >> > > > > >> > Do you have an example of this? As you said, it's unlikely > >> that > >> > > this > >> > > > > >> would > >> > > > > >> > occur in practice, also to me. > >> > > > > >> > > >> > > > > >> > > If a plugin explicitly > >> > > > > >> > implements ConfigSpecifier, would that break compatibility? > >> > > > > >> > > >> > > > > >> > In this case, it should. > >> > > > > >> > > >> > > > > >> > > If a plugin > >> > > > > >> > doesn't explicitly implement ConfigSpecifier, would that > >> break > >> > > > > >> > compatibility? > >> > > > > >> > > >> > > > > >> > This should not break it. > >> > > > > >> > > >> > > > > >> > > These are the two cases that come to mind immediately but > >> if > >> > > > > >> > any others occur to you feel free to document them as well. > >> > > > > >> > > >> > > > > >> > No other cases come to mind. I'll update the compatibility > >> section > >> > > > with > >> > > > > >> the > >> > > > > >> > forward compatibility consideration. > >> > > > > >> > > >> > > > > >> > > There's also the pluggable ConnectRestExtension > >> > > > > >> > and ConnectorClientConfigOverridePolicy interfaces. Neither > >> > > > currently > >> > > > > >> > exposes a config method but it wouldn't be out of the > >> question to > >> > > > add > >> > > > > >> one > >> > > > > >> > now to them with a default implementation that returns an > >> empty > >> > > > > >> ConfigDef. > >> > > > > >> > > >> > > > > >> > Well, I would say that since they are `Configurable`, I > could > >> > > expect > >> > > > > >> that > >> > > > > >> > maybe in some future there could also be the possibility to > >> > > declare > >> > > > a > >> > > > > >> > specific configuration. > >> > > > > >> > So your proposal to add it and implement it as a default > >> seems > >> > > good > >> > > > to > >> > > > > >> me. > >> > > > > >> > > >> > > > > >> > Regards, > >> > > > > >> > Mario. > >> > > > > >> > > >> > > > > >> > > >> > > > > >> > Il giorno gio 22 gen 2026 alle ore 04:33 Chris Egerton < > >> > > > > >> > [email protected]> ha scritto: > >> > > > > >> > > >> > > > > >> > > Hi Mario, > >> > > > > >> > > > >> > > > > >> > > Thanks for the KIP! My thoughts: > >> > > > > >> > > > >> > > > > >> > > 1. (Minor) The Javadoc for HeaderConverter::config is a > >> little > >> > > > > >> > strange--is > >> > > > > >> > > it meant to refer to "this set of header converters" or > >> should > >> > > it > >> > > > > >> just be > >> > > > > >> > > "this header converter"? > >> > > > > >> > > > >> > > > > >> > > 2. The compatibility problem with Connect is always > >> gnarly. The > >> > > > > >> section > >> > > > > >> > on > >> > > > > >> > > backward compatibility is very well done in that it > >> demonstrates > >> > > > with > >> > > > > >> > > certainty that older plugins will be able to run smoothly > >> on > >> > > newer > >> > > > > >> > versions > >> > > > > >> > > of the Connect runtime. However, there's also the > question > >> of > >> > > > whether > >> > > > > >> > newer > >> > > > > >> > > plugins (compiled against a future version of the Connect > >> API > >> > > > with the > >> > > > > >> > > change proposed in this KIP) will continue to be > >> compatible with > >> > > > older > >> > > > > >> > > versions of the Connect runtime. For example, there's the > >> > > obvious > >> > > > case > >> > > > > >> > > where a plugin instantiates an object with a > >> left-hand-type of > >> > > > > >> > > ConfigSpecifier in its constructor. That plugin would be > >> > > > incompatible > >> > > > > >> > with > >> > > > > >> > > older versions of Connect. It's unlikely that this would > >> occur > >> > > in > >> > > > > >> > practice > >> > > > > >> > > and even if it does, I think it's fine to accept that as > a > >> > > > tradeoff. > >> > > > > >> > > However, it'd be nice to see the compatibility section > >> explore > >> > > > exactly > >> > > > > >> > what > >> > > > > >> > > would render a plugin compiled against the newer Connect > >> API > >> > > > > >> incompatible > >> > > > > >> > > with older versions of the Connect runtime. If a plugin > >> > > explicitly > >> > > > > >> > > implements ConfigSpecifier, would that break > >> compatibility? If a > >> > > > > >> plugin > >> > > > > >> > > doesn't explicitly implement ConfigSpecifier, would that > >> break > >> > > > > >> > > compatibility? These are the two cases that come to mind > >> > > > immediately > >> > > > > >> but > >> > > > > >> > if > >> > > > > >> > > any others occur to you feel free to document them as > >> well. This > >> > > > > >> coverage > >> > > > > >> > > can also help guide us in how to document the interface > >> if/when > >> > > we > >> > > > > >> add it > >> > > > > >> > > to make it clear to plugin developers how to avoid > >> rendering > >> > > their > >> > > > > >> work > >> > > > > >> > > accidentally incompatibile with older versions of the > >> Connect > >> > > > runtime. > >> > > > > >> > > > >> > > > > >> > > 3. There's also the pluggable ConnectRestExtension > >> > > > > >> > > and ConnectorClientConfigOverridePolicy interfaces. > Neither > >> > > > currently > >> > > > > >> > > exposes a config method but it wouldn't be out of the > >> question > >> > > to > >> > > > add > >> > > > > >> one > >> > > > > >> > > now to them with a default implementation that returns an > >> empty > >> > > > > >> > ConfigDef. > >> > > > > >> > > Thoughts? > >> > > > > >> > > > >> > > > > >> > > Cheers, > >> > > > > >> > > > >> > > > > >> > > Chris > >> > > > > >> > > > >> > > > > >> > > On Wed, Jan 21, 2026 at 10:33 AM Mario Fiore Vitale via > >> dev < > >> > > > > >> > > [email protected]> wrote: > >> > > > > >> > > > >> > > > > >> > > > Hi Everyone, > >> > > > > >> > > > > >> > > > > >> > > > I would like to start a discussion on KIP-1273: Improve > >> > > Connect > >> > > > > >> > > > configurable components discoverability [1]. > >> > > > > >> > > > > >> > > > > >> > > > Summary: > >> > > > > >> > > > The idea is to introduce a common ConfigSpecifier > >> interface > >> > > for > >> > > > > >> Kafka > >> > > > > >> > > > Connect components that expose configuration metadata. > By > >> > > > unifying > >> > > > > >> the > >> > > > > >> > > > existing config() method across connectors, converters, > >> > > > > >> > transformations, > >> > > > > >> > > > and predicates under a single contract, it simplifies > >> > > component > >> > > > > >> > > discovery, > >> > > > > >> > > > reduces code duplication and enables uniform tooling > for > >> > > > > >> configuration > >> > > > > >> > > > introspection, validation, documentation, and UI > >> generation. > >> > > The > >> > > > > >> change > >> > > > > >> > > is > >> > > > > >> > > > fully backward compatible and requires no modifications > >> to > >> > > > existing > >> > > > > >> > > > component implementations. > >> > > > > >> > > > > >> > > > > >> > > > [1] > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > >> > > > >> > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1273%3A+Improve+Connect+configurable+components+discoverability > >> > > > > >> > > > > >> > > > > >> > > > Regards, > >> > > > > >> > > > Mario > >> > > > > >> > > > > >> > > > > >> > > > >> > > > > >> > > >> > > > > >> > >> > > > > > > >> > > > > >> > > > >> > > >
