Enables transactions for the producer.

If using KafkaProducer.transactional or KafkaProducer.transactionalStream, then this will automatically be done when the producer is created. If not, then this function has to be called manually before using any of the transaction methods:

• KafkaProducer#transaction,
• KafkaProducer#produceTransactionally,
• KafkaProducer#produceAndCommitTransactionally

or an IllegalStateException exception will be raised.

Returns producer metrics.

Returns partition metadata for the given topic.

Produces the specified ProducerRecords in two steps: the first effect puts the records in the buffer of the producer, and the second effect waits for the records to send.

It's possible to flatten the result from this function to have an effect which both sends the records and waits for them to finish sending.

Waiting for individual records to send can substantially limit performance. In some cases, this is necessary, and so we might want to consider the following alternatives.

• Wait for the produced records in batches, improving the rate at which records are produced, but loosing the guarantee where produce >> otherAction means otherAction executes after the record has been sent.
  
• Run several produce.flatten >> otherAction concurrently, improving the rate at which records are produced, and still have otherAction execute after records have been sent, but losing the order of produced records.

Produces the ProducerRecords in the specified TransactionalProducerRecords in four steps: first a transaction is initialized, then the records are placed in the buffer of the producer, then the offsets of the records are sent to the transaction, and lastly the transaction is committed. If errors or cancellation occurs, the transaction is aborted. The returned effect succeeds if the whole transaction completes successfully.

Produces the ProducerRecords in the specified ProducerRecords in three steps: first a transaction is initialized, then the records are placed in the buffer of the producer, and lastly the transaction is committed. If errors or cancellation occurs, the transaction is aborted. The returned effect succeeds if the whole transaction completes successfully.

Return a resource which handles the transaction lifecycle.

The returned resource begins a transaction on use and:

• commits the transaction if the use finishes successfully, or
• aborts the transaction if an error occurs or the process is canceled.

Note initTransactions must have been called before using this method, either manually or automatically through the use of KafkaProducer.transactional or KafkaProducer.transactionalStream.

Also note only one transaction can be open at any time. If a second transaction is started within the lifecycle of a first transaction, the second transaction will deadlock.

producer.transaction.surround {
  producer.transaction.surround { // deadlocks waiting for the outer transaction
    IO.unit
  }
}