visortelle commented on code in PR #712: URL: https://github.com/apache/pulsar-site/pull/712#discussion_r1508028602
########## docs/txn-advanced-features.md: ########## @@ -37,10 +37,34 @@ If you want to enable authentication with transactions, follow the steps below. 2. [Configure authentication](security-overview/#authentication) in a Pulsar client. +## Select transaction isolation level + +To enhance the flexibility of Pulsar transactions, they support two distinct isolation levels: +- `READ_COMMITTED`(default): The consumer can only consume all transactional messages that have been committed. +- `READ_UNCOMMITTED`: The consumer can consume all messages, even transactional messages that have been aborted. + +For different scenarios, they use different subscriptions and choose different isolation levels. One needs transaction, one does not. In general, multiple subscriptions of the same topic do not all +require transaction guarantees. Some want low latency without the exact-once semantic guarantee (like Real-Time Monitoring System), and some must require the exactly-once guarantee (like Business Processing System). +Users can freely choose different isolation levels according to different scenarios. Review Comment: ```suggestion For different scenarios, they use different subscriptions and choose different isolation levels. One needs transaction, one does not. In general, multiple subscriptions of the same topic do not all require transaction guarantees. Some want low latency without the exact-once semantic guarantee (like a real-time monitoring system), and some must require the exactly-once guarantee (e.g., business processing systems). Users can freely choose different isolation levels according to different scenarios. ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
