Pulsar transactions support the following guarantee.
Atomic multi-partition writes and multi-subscription acknowledges
Transactions enable atomic writes to multiple topics and partitions. A batch of messages in a transaction can be received from, produced to, and acknowledged by many partitions. All the operations involved in a transaction succeed or fail as a single unit.
Read transactional message
All the messages in a transaction are available only for consumers until the transaction is committed.
Acknowledge transactional message
A message is acknowledged successfully only once by a consumer under the subscription when acknowledging the message with the transaction ID.