Hi, Yash. I'm not sure I quite understand why it would be "easier" for connector > developers to account for implementing two different overloaded `put` > methods (assuming that they want to use this new feature) versus using a > try-catch block around `SinkRecord` access methods?
Using a try-catch to try around an API method that *might* be there is a very unusual thing for most developers. Unfortunately, we've had to resort to this atypical approach with Connect in places when there was no good alternative. We seem to relying upon pattern because it's easier for us, not because it offers a better experience for Connector developers. IMO, if there's a practical alternative that uses normal development practices and techniques, then we should use that alternative. IIUC, there is at least one practical alternative for this KIP that would not require developers to use the unusual try-catch to handle the case where methods are not found. I also think having two `put` methods is easier when the Connector has to do different things for different Connect runtimes, too. One of those methods is called by newer Connect runtimes with the new behavior, and the other method is called by an older Connect runtime. Of course, if the developer does not need separate methods, they can easily have the older `put` method simply delegate to the newer method. Finally, this gives us a roadmap for *eventually* deprecating the older method, once the Connect runtime versions without this change are old enough. I think the advantage of going with the > proposed approach in the KIP is that it wouldn't require extra book-keeping > (the Map<SinkRecord, > TopicPartition> in `WorkerSinkTask` in your proposed approach) > The connector does have to do some of this bookkeeping in how they track the topic partition offsets used in the `preCommit`, and the pre-commit methods use the same `Map<TopicPartition, OffsetAndMetadata> currentOffsets` data structure I'm suggesting be used. I hope that helps. Best regards, Randall On Mon, Sep 26, 2022 at 9:38 AM Yash Mayya <yash.ma...@gmail.com> wrote: > Hi Randall, > > Thanks for reviewing the KIP! > > > That latter logic can get quite ugly. > > I'm not sure I quite understand why it would be "easier" for connector > developers to account for implementing two different overloaded `put` > methods (assuming that they want to use this new feature) versus using a > try-catch block around `SinkRecord` access methods? In both cases, a > connector developer would need to write additional code in order to ensure > that their connector continues working with older Connect runtimes. > Furthermore, we would probably need to carefully document how the > implementation for the older `put` method should look like for connectors > that want to use this new feature. I think the advantage of going with the > proposed approach in the KIP is that it wouldn't require extra book-keeping > (the Map<SinkRecord, > TopicPartition> in `WorkerSinkTask` in your proposed approach) and also the > fact that the try-catch based logic is an already established pattern > through > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-610%3A+Error+Reporting+in+Sink+Connectors > and other KIPs which added methods to source/sink connector/task contexts. > > Let me know if you still feel that having a new overloaded put method is a > cleaner solution and I'd be happy to reconsider! > > Thanks, > Yash > > On Thu, Sep 22, 2022 at 11:18 PM Randall Hauch <rha...@gmail.com> wrote: > > > Hi, Yash. Thanks for picking up this KIP and discussion. > > > > The KIP includes this rejected alternative: > > > > > 4. Update SinkTask.put in any way to pass the new information outside > > > SinkRecord (e.g. a Map or a derived class) > > > > > > - > > > > > > Much more disruptive change without considerable pros > > > > > > > > One advantage about doing this is that sink connector implementations can > > more easily implement two different "put(...)" methods to handle running > in > > a variety of runtimes, without having to use try-catch logic around the > > newer SinkRecord access methods. That latter logic can get quite ugly. > > > > For example, the existing `put` method has this signature: > > > > public abstract void put(Collection<SinkRecord> records); > > > > If we added an overloaded method that passed in a map of the old > > topic+partition for each record (and defined the absence of an entry as > > having an unchanged topic and partition): > > > > public void put(Collection<SinkRecord> records, Map<SinkRecord, > > TopicPartition> updatedTopicPartitions) { > > put(records); > > } > > > > then a `SinkTask` implementation that wants to use this new feature could > > simply implement both methods: > > > > public void put(Collection<SinkRecord> records) { > > // Running in an older runtime, so no tracking of SMT-modified topic > names > > or partitions > > put(records, Map.of()); > > } > > > > public void put(Collection<SinkRecord> records, Map<SinkRecord, > > TopicPartition> updatedTopicPartitions) { > > // real logic here > > } > > > > This seems a lot easier than having to use try-catch logic, yet still > > allows sink connectors to utilize the new functionality and still work > with > > older Connect runtimes. > > > > WDYT? > > > > Randall > > > > > > On Thu, Sep 8, 2022 at 7:03 AM Yash Mayya <yash.ma...@gmail.com> wrote: > > > > > Hi all, > > > > > > I would like to (re)start a new discussion thread on KIP-793 (Kafka > > > Connect) which proposes some additions to the public SinkRecord > interface > > > in order to support topic mutating SMTs for sink connectors that do > their > > > own offset tracking. > > > > > > Links: > > > > > > KIP: > > > > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=191336830 > > > > > > Older discussion thread: > > > https://lists.apache.org/thread/00kcth6057jdcsyzgy1x8nb2s1cymy8h, > > > https://lists.apache.org/thread/rzqkm0q5y5v3vdjhg8wqppxbkw7nyopj > > > > > > Jira: https://issues.apache.org/jira/browse/KAFKA-13431 > > > > > > > > > Thanks, > > > Yash > > > > > >
