Hi Chris,
The difference is in the Task Classes, no difference for value/key
convertors.
I don’t see log messages for graceful shutdown. I am not clear on what you
mean by shutting down the task.
I called the commit operation for the successful records. Should I perform
any other steps if I have an invalid record?
Please advise.
Thanks,
Nitty
On Mon, Mar 13, 2023 at 3:42 PM Chris Egerton <chr...@aiven.io.invalid>
wrote:
> Hi Nitty,
>
> Thanks again for all the details here, especially the log messages.
>
> > The below mentioned issue is happening for Json connector only. Is there
> any difference with asn1,binary,csv and json connector?
>
> Can you clarify if the difference here is in the Connector/Task classens,
> or if it's in the key/value converters that are configured for the
> connector? The key/value converters are configured using the
> "key.converter" and "value.converter" property and, if problems arise with
> them, the task will fail and, if it has a non-empty ongoing transaction,
> that transaction will be automatically aborted since we close the task's
> Kafka producer when it fails (or shuts down gracefully).
>
> With regards to these log messages:
>
> > org.apache.kafka.common.errors.ProducerFencedException: There is a newer
> producer with the same transactionalId which fences the current one.
>
> It looks like your tasks aren't shutting down gracefully in time, which
> causes them to be fenced out by the Connect framework later on. Do you see
> messages like "Graceful stop of task <TASK ID HERE> failed" in the logs for
> your Connect worker?
>
> Cheers,
>
> Chris
>
> On Mon, Mar 13, 2023 at 10:58 AM NITTY BENNY <nittybe...@gmail.com> wrote:
>
> > Hi Chris,
> >
> > As you said, the below message is coming when I call an abort if there is
> > an invalid record, then for the next transaction I can see the below
> > message and then the connector will be stopped.
> > 2023-03-13 14:28:26,043 INFO [json-sftp-source-connector|task-0] Aborting
> > transaction for batch as requested by connector
> > (org.apache.kafka.connect.runtime.ExactlyOnceWorkerSourceTask)
> > [task-thread-json-sftp-source-connector-0]
> > 2023-03-13 14:28:26,043 INFO [json-sftp-source-connector|task-0]
> [Producer
> > clientId=connector-producer-json-sftp-source-connector-0,
> > transactionalId=connect-cluster-json-sftp-source-connector-0] Aborting
> > incomplete transaction (org.apache.kafka.clients.producer.KafkaProducer)
> > [task-thread-json-sftp-source-connector-0]
> >
> > The issue with InvalidProducerEpoch is happening when I call the commit
> if
> > there is an invalid record, and in the next transaction I am getting
> > InvalidProducerEpoch Exception and the messages are copied in the
> previous
> > email. I don't know if this will also be fixed by your bug fix.I am using
> > kafka 3.3.1 version as of now.
> >
> > Thanks,
> > Nitty
> >
> >
> > On Mon, Mar 13, 2023 at 10:47 AM NITTY BENNY <nittybe...@gmail.com>
> wrote:
> >
> > > Hi Chris,
> > >
> > > The below mentioned issue is happening for Json connector only. Is
> there
> > > any difference with asn1,binary,csv and json connector?
> > >
> > > Thanks,
> > > Nitty
> > >
> > > On Mon, Mar 13, 2023 at 9:16 AM NITTY BENNY <nittybe...@gmail.com>
> > wrote:
> > >
> > >> Hi Chris,
> > >>
> > >> Sorry Chris, I am not able to reproduce the above issue.
> > >>
> > >> I want to share with you one more use case I found.
> > >> The use case is in the first batch it returns 2 valid records and then
> > in
> > >> the next batch it is an invalid record.Below is the transaction_state
> > >> topic, when I call a commit while processing an invalid record.
> > >>
> > >>
> >
> connect-cluster-json-sftp-source-connector-0::TransactionMetadata(transactionalId=connect-cluster-json-sftp-source-connector-0,
> > >> producerId=11, producerEpoch=2, txnTimeoutMs=60000, state=*Ongoing*,
> > >> pendingState=None, topicPartitions=HashSet(streams-input-2),
> > >> txnStartTimestamp=1678620463834, txnLastUpdateTimestamp=1678620463834)
> > >>
> > >> then after some time I saw the below states as well,
> > >>
> > >>
> >
> connect-cluster-json-sftp-source-connector-0::TransactionMetadata(transactionalId=connect-cluster-json-sftp-source-connector-0,
> > >> producerId=11, producerEpoch=3, txnTimeoutMs=60000,
> > state=*PrepareAbort*,
> > >> pendingState=None, topicPartitions=HashSet(streams-input-2),
> > >> txnStartTimestamp=1678620463834, txnLastUpdateTimestamp=1678620526119)
> > >>
> >
> connect-cluster-json-sftp-source-connector-0::TransactionMetadata(transactionalId=connect-cluster-json-sftp-source-connector-0,
> > >> producerId=11, producerEpoch=3, txnTimeoutMs=60000,
> > state=*CompleteAbort*,
> > >> pendingState=None, topicPartitions=HashSet(),
> > >> txnStartTimestamp=1678620463834, txnLastUpdateTimestamp=1678620526121)
> > >>
> > >> Later for the next transaction, when it returns the first batch below
> is
> > >> the logs I can see.
> > >>
> > >> Transiting to abortable error state due to
> > >> org.apache.kafka.common.errors.InvalidProducerEpochException: Producer
> > >> attempted to produce with an old epoch.
> > >> (org.apache.kafka.clients.producer.internals.TransactionManager)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> 2023-03-12 11:32:45,220 ERROR [json-sftp-source-connector|task-0]
> > >> ExactlyOnceWorkerSourceTask{id=json-sftp-source-connector-0} failed to
> > send
> > >> record to streams-input:
> > >> (org.apache.kafka.connect.runtime.AbstractWorkerSourceTask)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> org.apache.kafka.common.errors.InvalidProducerEpochException: Producer
> > >> attempted to produce with an old epoch.
> > >> 2023-03-12 11:32:45,222 INFO [json-sftp-source-connector|task-0]
> > >> [Producer clientId=connector-producer-json-sftp-source-connector-0,
> > >> transactionalId=connect-cluster-json-sftp-source-connector-0]
> > Transiting to
> > >> fatal error state due to
> > >> org.apache.kafka.common.errors.ProducerFencedException: There is a
> newer
> > >> producer with the same transactionalId which fences the current one.
> > >> (org.apache.kafka.clients.producer.internals.TransactionManager)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> 2023-03-12 11:32:45,222 ERROR [json-sftp-source-connector|task-0]
> > >> [Producer clientId=connector-producer-json-sftp-source-connector-0,
> > >> transactionalId=connect-cluster-json-sftp-source-connector-0] Aborting
> > >> producer batches due to fatal error
> > >> (org.apache.kafka.clients.producer.internals.Sender)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> org.apache.kafka.common.errors.ProducerFencedException: There is a
> newer
> > >> producer with the same transactionalId which fences the current one.
> > >> 2023-03-12 11:32:45,222 ERROR [json-sftp-source-connector|task-0]
> > >> ExactlyOnceWorkerSourceTask{id=json-sftp-source-connector-0} Failed to
> > >> flush offsets to storage:
> > >> (org.apache.kafka.connect.runtime.ExactlyOnceWorkerSourceTask)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> org.apache.kafka.common.errors.ProducerFencedException: There is a
> newer
> > >> producer with the same transactionalId which fences the current one.
> > >> 2023-03-12 11:32:45,224 ERROR [json-sftp-source-connector|task-0]
> > >> ExactlyOnceWorkerSourceTask{id=json-sftp-source-connector-0} failed to
> > send
> > >> record to streams-input:
> > >> (org.apache.kafka.connect.runtime.AbstractWorkerSourceTask)
> > >> [kafka-producer-network-thread |
> > >> connector-producer-json-sftp-source-connector-0]
> > >> org.apache.kafka.common.errors.ProducerFencedException: There is a
> newer
> > >> producer with the same transactionalId which fences the current one.
> > >> 2023-03-12 11:32:45,222 ERROR
> > [json-sftp-source-connector|task-0|offsets]
> > >> ExactlyOnceWorkerSourceTask{id=json-sftp-source-connector-0} Failed to
> > >> commit producer transaction
> > >> (org.apache.kafka.connect.runtime.ExactlyOnceWorkerSourceTask)
> > >> [task-thread-json-sftp-source-connector-0]
> > >> org.apache.kafka.common.errors.ProducerFencedException: There is a
> newer
> > >> producer with the same transactionalId which fences the current one.
> > >> 2023-03-12 11:32:45,225 ERROR [json-sftp-source-connector|task-0]
> > >> ExactlyOnceWorkerSourceTask{id=json-sftp-source-connector-0} Task
> threw
> > an
> > >> uncaught and unrecoverable exception. Task is being killed and will
> not
> > >> recover until manually restarted
> > >> (org.apache.kafka.connect.runtime.WorkerTask)
> > >> [task-thread-json-sftp-source-connector-0]
> > >>
> > >> Do you know why it is showing an abort state even if I call commit?
> > >>
> > >> I tested one more scenario, When I call the commit I saw the below
> > >>
> >
> connect-cluster-json-sftp-source-connector-0::TransactionMetadata(transactionalId=connect-cluster-json-sftp-source-connector-0,
> > >> producerId=11, producerEpoch=2, txnTimeoutMs=60000, state=*Ongoing*,
> > >> pendingState=None, topicPartitions=HashSet(streams-input-2),
> > >> txnStartTimestamp=1678620463834, txnLastUpdateTimestamp=1678620463834)
> > >> Then, before changing the states to Abort, I dropped the next file
> then
> > I
> > >> dont see any issues. Previous transaction
> > >> as well as the current transaction are committed.
> > >>
> > >> Thank you for your support.
> > >>
> > >> Thanks,
> > >> Nitty
> > >>
> > >> On Fri, Mar 10, 2023 at 8:04 PM Chris Egerton <chr...@aiven.io.invalid
> >
> > >> wrote:
> > >>
> > >>> Hi Nitty,
> > >>>
> > >>> > I called commitTransaction when I reach the first error record, but
> > >>> commit is not happening for me. Kafka connect tries to abort the
> > >>> transaction automatically
> > >>>
> > >>> This is really interesting--are you certain that your task never
> > invoked
> > >>> TransactionContext::abortTransaction in this case? I'm looking over
> the
> > >>> code base and it seems fairly clear that the only thing that could
> > >>> trigger
> > >>> a call to KafkaProducer::abortTransaction is a request by the task to
> > >>> abort
> > >>> a transaction (either for a next batch, or for a specific record). It
> > may
> > >>> help to run the connector in a debugger and/or look for "Aborting
> > >>> transaction for batch as requested by connector" or "Aborting
> > transaction
> > >>> for record on topic <TOPIC NAME HERE> as requested by connector" log
> > >>> messages (which will be emitted at INFO level by
> > >>> the org.apache.kafka.connect.runtime.ExactlyOnceWorkerSourceTask
> class
> > if
> > >>> the task is requesting an abort).
> > >>>
> > >>> Regardless, I'll work on a fix for the bug with aborting empty
> > >>> transactions. Thanks for helping uncover that one!
> > >>>
> > >>> Cheers,
> > >>>
> > >>> Chris
> > >>>
> > >>> On Thu, Mar 9, 2023 at 6:36 PM NITTY BENNY <nittybe...@gmail.com>
> > wrote:
> > >>>
> > >>> > Hi Chris,
> > >>> >
> > >>> > We have a use case to commit previous successful records and stop
> the
> > >>> > processing of the current file and move on with the next file. To
> > >>> achieve
> > >>> > that I called commitTransaction when I reach the first error
> record,
> > >>> but
> > >>> > commit is not happening for me. Kafka connect tries to abort the
> > >>> > transaction automatically, I checked the _transaction_state topic
> and
> > >>> > states marked as PrepareAbort and CompleteAbort. Do you know why
> > kafka
> > >>> > connect automatically invokes abort instead of the implicit commit
> I
> > >>> > called?
> > >>> > Then as a result, when I tries to parse the next file - say ABC, I
> > saw
> > >>> the
> > >>> > logs "Aborting incomplete transaction" and ERROR: "Failed to sent
> > >>> record to
> > >>> > topic", and we lost the first batch of records from the current
> > >>> transaction
> > >>> > in the file ABC.
> > >>> >
> > >>> > Is it possible that there's a case where an abort is being
> requested
> > >>> while
> > >>> > the current transaction is empty (i.e., the task hasn't returned
> any
> > >>> > records from SourceTask::poll since the last transaction was
> > >>> > committed/aborted)? --- Yes, that case is possible for us. There
> is a
> > >>> case
> > >>> > where the first record itself an error record.
> > >>> >
> > >>> > Thanks,
> > >>> > Nitty
> > >>> >
> > >>> > On Thu, Mar 9, 2023 at 3:48 PM Chris Egerton
> <chr...@aiven.io.invalid
> > >
> > >>> > wrote:
> > >>> >
> > >>> > > Hi Nitty,
> > >>> > >
> > >>> > > Thanks for the code examples and the detailed explanations, this
> is
> > >>> > really
> > >>> > > helpful!
> > >>> > >
> > >>> > > > Say if I have a file with 5 records and batch size is 2, and in
> > my
> > >>> 3rd
> > >>> > > batch I have one error record then in that batch, I dont have a
> > valid
> > >>> > > record to call commit or abort. But I want to commit all the
> > previous
> > >>> > > batches that were successfully parsed. How do I do that?
> > >>> > >
> > >>> > > An important thing to keep in mind with the TransactionContext
> API
> > is
> > >>> > that
> > >>> > > all records that a task returns from SourceTask::poll are
> > implicitly
> > >>> > > included in a transaction. Invoking
> > >>> SourceTaskContext::transactionContext
> > >>> > > doesn't alter this or cause transactions to start being used;
> > >>> everything
> > >>> > is
> > >>> > > already in a transaction, and the Connect runtime automatically
> > >>> begins
> > >>> > > transactions for any records it sees from the task if it hasn't
> > >>> already
> > >>> > > begun one. It's also valid to return a null or empty list of
> > records
> > >>> from
> > >>> > > SourceTask::poll. So in this case, you can invoke
> > >>> > > transactionContext.commitTransaction() (the no-args variant) and
> > >>> return
> > >>> > an
> > >>> > > empty batch from SourceTask::poll, which will cause the
> transaction
> > >>> > > containing the 4 valid records that were returned in the last 2
> > >>> batches
> > >>> > to
> > >>> > > be committed.
> > >>> > >
> > >>> > > FWIW, I would be a little cautious about this approach. Many
> times
> > >>> it's
> > >>> > > better to fail fast on invalid data; it might be worth it to at
> > least
> > >>> > allow
> > >>> > > users to configure whether the connector fails on invalid data,
> or
> > >>> > silently
> > >>> > > skips over it (which is what happens when transactions are
> > aborted).
> > >>> > >
> > >>> > > > Why is abort not working without adding the last record to the
> > >>> list?
> > >>> > >
> > >>> > > Is it possible that there's a case where an abort is being
> > requested
> > >>> > while
> > >>> > > the current transaction is empty (i.e., the task hasn't returned
> > any
> > >>> > > records from SourceTask::poll since the last transaction was
> > >>> > > committed/aborted)? I think this may be a bug in the Connect
> > >>> framework
> > >>> > > where we don't check to see if a transaction is already open
> when a
> > >>> task
> > >>> > > requests that a transaction be aborted, which can cause tasks to
> > fail
> > >>> > (see
> > >>> > > https://issues.apache.org/jira/browse/KAFKA-14799 for more
> > details).
> > >>> > >
> > >>> > > Cheers,
> > >>> > >
> > >>> > > Chris
> > >>> > >
> > >>> > >
> > >>> > > On Wed, Mar 8, 2023 at 6:44 PM NITTY BENNY <nittybe...@gmail.com
> >
> > >>> wrote:
> > >>> > >
> > >>> > > > Hi Chris,
> > >>> > > >
> > >>> > > > I am not sure if you are able to see the images I shared with
> > you .
> > >>> > > > Copying the code snippet below,
> > >>> > > >
> > >>> > > > if (expectedRecordCount >= 0) {
> > >>> > > > int missingCount = expectedRecordCount - (int)
> this.
> > >>> > > > recordOffset() - 1;
> > >>> > > > if (missingCount > 0) {
> > >>> > > > if (transactionContext != null) {
> > >>> > > > isMissedRecords = true;
> > >>> > > > } else {
> > >>> > > > throw new DataException(String.format("Missing
> %d
> > >>> > records
> > >>> > > > (expecting %d, actual %d)", missingCount, expectedRecordCount,
> > >>> this.
> > >>> > > > recordOffset()));
> > >>> > > > }
> > >>> > > > } else if (missingCount < 0) {
> > >>> > > > if (transactionContext != null) {
> > >>> > > > isMissedRecords = true;
> > >>> > > > } else {
> > >>> > > > throw new DataException(String.format("Too many
> > >>> records
> > >>> > > > (expecting %d, actual %d)", expectedRecordCount,
> > >>> this.recordOffset()));
> > >>> > > > }
> > >>> > > > }
> > >>> > > > }
> > >>> > > > addLastRecord(records, null, value);
> > >>> > > > }
> > >>> > > >
> > >>> > > >
> > >>> > > >
> > >>> > > > //asn1 or binary abort
> > >>> > > > if((config.parseErrorThreshold != null &&
> parseErrorCount
> > >>> >=
> > >>> > > > config.parseErrorThreshold
> > >>> > > > && lastbatch && transactionContext != null) ||
> > >>> (isMissedRecords
> > >>> > > > && transactionContext != null && lastbatch)) {
> > >>> > > > log.info("Transaction is aborting");
> > >>> > > > log.info("records = {}", records);
> > >>> > > > if (!records.isEmpty()) {
> > >>> > > > log.info("with record");
> > >>> > > >
> > >>> > > transactionContext.abortTransaction(records.get(records.size
> > >>> > > > ()-1));
> > >>> > > > } else {
> > >>> > > > log.info("without record");
> > >>> > > > transactionContext.abortTransaction();
> > >>> > > > }
> > >>> > > >
> > >>> > > > Thanks,
> > >>> > > > Nitty
> > >>> > > >
> > >>> > > > On Wed, Mar 8, 2023 at 11:38 PM NITTY BENNY <
> > nittybe...@gmail.com>
> > >>> > > wrote:
> > >>> > > >
> > >>> > > >> Hi Chris,
> > >>> > > >> Sorry for the typo in my previous email.
> > >>> > > >>
> > >>> > > >> Regarding the point 2,* the task returns a batch of records
> from
> > >>> > > >> SourceTask::poll (and, if using*
> > >>> > > >>
> > >>> > > >>
> > >>> > > >> *the per-record API provided by the TransactionContext class,
> > >>> includes
> > >>> > > >> atleast one record that should trigger a transaction
> > commit/abort
> > >>> in
> > >>> > > >> thatbatch)*
> > >>> > > >> What if I am using the API without passing a record? We have 2
> > >>> types
> > >>> > of
> > >>> > > >> use cases, one where on encountering an error record, we want
> to
> > >>> > commit
> > >>> > > >> previous successful batches and disregard the failed record
> and
> > >>> > upcoming
> > >>> > > >> batches. In this case we created the transactionContext just
> > >>> before
> > >>> > > reading
> > >>> > > >> the file (file is our transaction boundary).Say if I have a
> file
> > >>> with
> > >>> > 5
> > >>> > > >> records and batch size is 2, and in my 3rd batch I have one
> > error
> > >>> > record
> > >>> > > >> then in that batch, I dont have a valid record to call commit
> or
> > >>> > abort.
> > >>> > > But
> > >>> > > >> I want to commit all the previous batches that were
> successfully
> > >>> > parsed.
> > >>> > > >> How do I do that?
> > >>> > > >>
> > >>> > > >> Second use case is where I want to abort a transaction if the
> > >>> record
> > >>> > > >> count doesn't match.
> > >>> > > >> Code Snippet :
> > >>> > > >> [image: image.png]
> > >>> > > >> There are no error records in this case. If you see I added
> the
> > >>> > > condition
> > >>> > > >> of transactionContext check to implement exactly once, without
> > >>> > > >> transaction it was just throwing the exception without calling
> > the
> > >>> > > >> addLastRecord() method and in the catch block it just logs the
> > >>> message
> > >>> > > and
> > >>> > > >> return the list of records without the last record to
> poll().To
> > >>> make
> > >>> > it
> > >>> > > >> work, I called the method addLastRecord() in this case, so it
> is
> > >>> not
> > >>> > > >> throwing the exception and list has last record as well. Then
> I
> > >>> called
> > >>> > > the
> > >>> > > >> abort, everything got aborted. Why is abort not working
> without
> > >>> adding
> > >>> > > the
> > >>> > > >> last record to the list?
> > >>> > > >> [image: image.png]
> > >>> > > >>
> > >>> > > >> Code to call abort.
> > >>> > > >>
> > >>> > > >>
> > >>> > > >>
> > >>> > > >>
> > >>> > > >> Thanks,
> > >>> > > >> Nitty
> > >>> > > >>
> > >>> > > >> On Wed, Mar 8, 2023 at 4:26 PM Chris Egerton
> > >>> <chr...@aiven.io.invalid
> > >>> > >
> > >>> > > >> wrote:
> > >>> > > >>
> > >>> > > >>> Hi Nitty,
> > >>> > > >>>
> > >>> > > >>> I'm a little confused about what you mean by this part:
> > >>> > > >>>
> > >>> > > >>> > transaction is not getting completed because it is not
> > >>> commiting
> > >>> > the
> > >>> > > >>> transaction offest.
> > >>> > > >>>
> > >>> > > >>> The only conditions required for a transaction to be
> completed
> > >>> when a
> > >>> > > >>> connector is defining its own transaction boundaries are:
> > >>> > > >>>
> > >>> > > >>> 1. The task requests a transaction commit/abort from the
> > >>> > > >>> TransactionContext
> > >>> > > >>> 2. The task returns a batch of records from SourceTask::poll
> > >>> (and, if
> > >>> > > >>> using
> > >>> > > >>> the per-record API provided by the TransactionContext class,
> > >>> includes
> > >>> > > at
> > >>> > > >>> least one record that should trigger a transaction
> commit/abort
> > >>> in
> > >>> > that
> > >>> > > >>> batch)
> > >>> > > >>>
> > >>> > > >>> The Connect runtime should automatically commit source
> offsets
> > to
> > >>> > Kafka
> > >>> > > >>> whenever a transaction is completed, either by commit or
> abort.
> > >>> This
> > >>> > is
> > >>> > > >>> because transactions should only be aborted for data that
> > should
> > >>> > never
> > >>> > > be
> > >>> > > >>> re-read by the connector; if there is a validation error that
> > >>> should
> > >>> > be
> > >>> > > >>> handled by reconfiguring the connector, then the task should
> > >>> throw an
> > >>> > > >>> exception instead of aborting the transaction.
> > >>> > > >>>
> > >>> > > >>> If possible, do you think you could provide a brief code
> > snippet
> > >>> > > >>> illustrating what your task is doing that's causing issues?
> > >>> > > >>>
> > >>> > > >>> Cheers,
> > >>> > > >>>
> > >>> > > >>> Chris (not Chrise 🙂)
> > >>> > > >>>
> > >>> > > >>> On Tue, Mar 7, 2023 at 10:17 AM NITTY BENNY <
> > >>> nittybe...@gmail.com>
> > >>> > > >>> wrote:
> > >>> > > >>>
> > >>> > > >>> > Hi Chrise,
> > >>> > > >>> >
> > >>> > > >>> > Thanks for sharing the details.
> > >>> > > >>> >
> > >>> > > >>> > Regarding the use case, For Asn1 source connector we have a
> > use
> > >>> > case
> > >>> > > to
> > >>> > > >>> > validate number of records in the file with the number of
> > >>> records
> > >>> > in
> > >>> > > >>> the
> > >>> > > >>> > header. So currently, if validation fails we are not
> sending
> > >>> the
> > >>> > last
> > >>> > > >>> > record to the topic. But after introducing exactly once
> with
> > >>> > > connector
> > >>> > > >>> > transaction boundary, I can see that if I call an abort
> when
> > >>> the
> > >>> > > >>> validation
> > >>> > > >>> > fails, transaction is not getting completed because it is
> not
> > >>> > > >>> commiting the
> > >>> > > >>> > transaction offest. I saw that transaction state changed to
> > >>> > > >>> CompleteAbort.
> > >>> > > >>> > So for my next transaction I am getting
> > >>> > InvalidProducerEpochException
> > >>> > > >>> and
> > >>> > > >>> > then task stopped after that. I tried calling the abort
> after
> > >>> > sending
> > >>> > > >>> last
> > >>> > > >>> > record to the topic then transaction getting completed.
> > >>> > > >>> >
> > >>> > > >>> > I dont know if I am doing anything wrong here.
> > >>> > > >>> >
> > >>> > > >>> > Please advise.
> > >>> > > >>> > Thanks,
> > >>> > > >>> > Nitty
> > >>> > > >>> >
> > >>> > > >>> > On Tue 7 Mar 2023 at 2:21 p.m., Chris Egerton
> > >>> > > <chr...@aiven.io.invalid
> > >>> > > >>> >
> > >>> > > >>> > wrote:
> > >>> > > >>> >
> > >>> > > >>> > > Hi Nitty,
> > >>> > > >>> > >
> > >>> > > >>> > > We've recently added some documentation on implementing
> > >>> > > exactly-once
> > >>> > > >>> > source
> > >>> > > >>> > > connectors here:
> > >>> > > >>> > >
> > >>> > > >>> >
> > >>> > > >>>
> > >>> > >
> > >>> >
> > >>>
> >
> https://kafka.apache.org/documentation/#connect_exactlyoncesourceconnectors
> > >>> > > >>> > > .
> > >>> > > >>> > > To quote a relevant passage from those docs:
> > >>> > > >>> > >
> > >>> > > >>> > > > In order for a source connector to take advantage of
> this
> > >>> > > support,
> > >>> > > >>> it
> > >>> > > >>> > > must be able to provide meaningful source offsets for
> each
> > >>> record
> > >>> > > >>> that it
> > >>> > > >>> > > emits, and resume consumption from the external system at
> > the
> > >>> > exact
> > >>> > > >>> > > position corresponding to any of those offsets without
> > >>> dropping
> > >>> > or
> > >>> > > >>> > > duplicating messages.
> > >>> > > >>> > >
> > >>> > > >>> > > So, as long as your source connector is able to use the
> > Kafka
> > >>> > > Connect
> > >>> > > >>> > > framework's offsets API correctly, it shouldn't be
> > necessary
> > >>> to
> > >>> > > make
> > >>> > > >>> any
> > >>> > > >>> > > other code changes to the connector.
> > >>> > > >>> > >
> > >>> > > >>> > > To enable exactly-once support for source connectors on
> > your
> > >>> > > Connect
> > >>> > > >>> > > cluster, see the docs section here:
> > >>> > > >>> > >
> > >>> > https://kafka.apache.org/documentation/#connect_exactlyoncesource
> > >>> > > >>> > >
> > >>> > > >>> > > With regard to transactions, a transactional producer is
> > >>> always
> > >>> > > >>> created
> > >>> > > >>> > > automatically for your connector by the Connect runtime
> > when
> > >>> > > >>> exactly-once
> > >>> > > >>> > > support is enabled on the worker. The only reason to set
> > >>> > > >>> > > "transaction.boundary" to "connector" is if your
> connector
> > >>> would
> > >>> > > >>> like to
> > >>> > > >>> > > explicitly define its own transaction boundaries. In this
> > >>> case,
> > >>> > it
> > >>> > > >>> sounds
> > >>> > > >>> > > like may be what you want; I just want to make sure to
> call
> > >>> out
> > >>> > > that
> > >>> > > >>> in
> > >>> > > >>> > > either case, you should not be directly instantiating a
> > >>> producer
> > >>> > in
> > >>> > > >>> your
> > >>> > > >>> > > connector code, but let the Kafka Connect runtime do that
> > for
> > >>> > you,
> > >>> > > >>> and
> > >>> > > >>> > just
> > >>> > > >>> > > worry about returning the right records from
> > SourceTask::poll
> > >>> > (and
> > >>> > > >>> > possibly
> > >>> > > >>> > > defining custom transactions using the TransactionContext
> > >>> API).
> > >>> > > >>> > >
> > >>> > > >>> > > With respect to your question about committing or
> aborting
> > in
> > >>> > > certain
> > >>> > > >>> > > circumstances, it'd be useful to know more about your use
> > >>> case,
> > >>> > > >>> since it
> > >>> > > >>> > > may not be necessary to define custom transaction
> > boundaries
> > >>> in
> > >>> > > your
> > >>> > > >>> > > connector at all.
> > >>> > > >>> > >
> > >>> > > >>> > > Cheers,
> > >>> > > >>> > >
> > >>> > > >>> > > Chris
> > >>> > > >>> > >
> > >>> > > >>> > >
> > >>> > > >>> > >
> > >>> > > >>> > > On Tue, Mar 7, 2023 at 7:21 AM NITTY BENNY <
> > >>> nittybe...@gmail.com
> > >>> > >
> > >>> > > >>> wrote:
> > >>> > > >>> > >
> > >>> > > >>> > > > Hi Team,
> > >>> > > >>> > > >
> > >>> > > >>> > > > Adding on top of this, I tried creating a
> > >>> TransactionContext
> > >>> > > >>> object and
> > >>> > > >>> > > > calling the commitTransaction and abortTranaction
> methods
> > >>> in
> > >>> > > source
> > >>> > > >>> > > > connectors.
> > >>> > > >>> > > > But the main problem I saw is that if there is any
> error
> > >>> while
> > >>> > > >>> parsing
> > >>> > > >>> > > the
> > >>> > > >>> > > > record, connect is calling an abort but we have a use
> > case
> > >>> to
> > >>> > > call
> > >>> > > >>> > commit
> > >>> > > >>> > > > in some cases. Is it a valid use case in terms of kafka
> > >>> > connect?
> > >>> > > >>> > > >
> > >>> > > >>> > > > Another Question - Should I use a transactional
> producer
> > >>> > instead
> > >>> > > >>> > > > creating an object of TransactionContext? Below is the
> > >>> > connector
> > >>> > > >>> > > > configuration I am using.
> > >>> > > >>> > > >
> > >>> > > >>> > > > exactly.once.support: "required"
> > >>> > > >>> > > > transaction.boundary: "connector"
> > >>> > > >>> > > >
> > >>> > > >>> > > > Could you please help me here?
> > >>> > > >>> > > >
> > >>> > > >>> > > > Thanks,
> > >>> > > >>> > > > Nitty
> > >>> > > >>> > > >
> > >>> > > >>> > > > On Tue, Mar 7, 2023 at 12:29 AM NITTY BENNY <
> > >>> > > nittybe...@gmail.com>
> > >>> > > >>> > > wrote:
> > >>> > > >>> > > >
> > >>> > > >>> > > > > Hi Team,
> > >>> > > >>> > > > > I am trying to implement exactly once behavior in our
> > >>> source
> > >>> > > >>> > connector.
> > >>> > > >>> > > > Is
> > >>> > > >>> > > > > there any sample source connector implementation
> > >>> available to
> > >>> > > >>> have a
> > >>> > > >>> > > look
> > >>> > > >>> > > > > at?
> > >>> > > >>> > > > > Regards,
> > >>> > > >>> > > > > Nitty
> > >>> > > >>> > > > >
> > >>> > > >>> > > >
> > >>> > > >>> > >
> > >>> > > >>> >
> > >>> > > >>>
> > >>> > > >>
> > >>> > >
> > >>> >
> > >>>
> > >>
> >
>
