8 min read

What’s New in Apache Pulsar 2.9.2

The Apache Pulsar community releases version 2.9.2! 60 contributors provided improvements and bug fixes that delivered 317 commits.

Highlights of this release are as below:

  • Transactions performance test tool is available. PR-11933
  • Brokers decrease the number of unacked messages. PR-13383
  • Readers continue to read data from the compacted ledgers. PR-13629

This blog walks through the most noteworthy changes grouped by the affected functionalities. For the complete list including all features, enhancements, and bug fixes, check out the Pulsar 2.9.2 Release Notes.

Notable bug fixes and enhancements

Readers continue to read data from the compacted ledgers. PR-13629


Previously, when topics were unloaded, some data was lost to be read by readers if they have consumed some messages from some compacted ledgers.


Rewound the reader cursor to the next message of the mark delete position if readCompacted = true.

Brokers decrease the number of unacked messages. PR-13383


Previously, brokers did not decrease the number of unacked messages if batch ack was enabled. Consequently, consumers were blocked if they reached maxUnackedMessagesPerConsumer limit.


Decreased the number of unacked messages when individualAckNormal was called.

Chunked messages can be queried through Pulsar SQL. PR-12720


Previously, chunked messages could not be queried through Pulsar SQL.


Add a chunked message map in PulsarRecordCursor to maintain incomplete chunked messages. If one chunked message was received completely, it would be offered in the message queue to wait for deserialization.

Support enable or disable schema upload at the broker level. PR-12786


Previously, Pulsar didn't support enabling or disabling schema upload at the broker level.


Added the configuration isSchemaAutoUploadEnabled on the broker side.

Readers can read the latest messages in compacted topics. PR-14449


Previously, readers were not able to read the latest messages in compacted topics if readers enabled readCompacted and all the data of topics has been compacted to compacted ledgers.


Added the forceReset configuration for the managed cursor, so that the cursor could be reset to a given position and readers can read data from compacted ledgers.

Transaction sequenceId can be recovered correctly. PR-13209


Previously, the wrong transaction sequenceId was recovered due to incorrect managedLedger properties.


Used ManagedLedgerInterceptor to update current sequenceId to managedLedger properties and more.

Transactions performance test tool is available. PR-11933


Previously, it was hard to test transaction performance (such as the delay and rate of sending and consuming messages) when opening a transaction.


Added PerformanceTransaction class to support this enhancement.

Port exhaustion and connection issues no longer exist in Pulsar Proxy. PR-14078


Previously, Pulsar proxy would get into a state where it stopped proxying broker connections while Admin API proxying kept working.


Optimized the proxy connection to fail-fast if the target broker was not active, added connect timeout handling to proxy connection, and more.

No race condition in OpSendMsgQueue when publishing messages. PR-14231


After the method getPendingQueueSize() was called and the send receipt came back, the peek from the pendingMessages might get NPE during the process.


Added a thread-safe message count object in OpSendMsgQueue for each compute process.

Change ContextClassLoader to NarClassLoader in AdditionalServlet. PR-13501


Previously, if a class was dynamically loaded by NarClassLoader, ClassNotFoundException occurred when it was used by the default class load.


Changed context class loader through Thread.currentThread().setContextClassLoader(classLoader) before every plugin calling back and changed the context class loader back to original class loader afterwards.

What’s Next?

If you are interested in learning more about Pulsar 2.9.2, you can download and try it out now!

Pulsar Summit San Francisco 2022 will take place on August 18th, 2022. Register now and help us make it an even bigger success by spreading the word on social media!

For more information about the Apache Pulsar project and current progress, visit the Pulsar website, follow the project on Twitter @apache_pulsar, and join Pulsar Slack!

Get involved

To get started, you can download Pulsar directly or you can spin up a Pulsar cluster with a free 30-day trial of StreamNative Cloud! We also offer technical consulting and expert training to help get your organization started. As always, we are highly responsive to your feedback. Feel free to contact us if you have any questions at any time. We look forward to hearing from you and stay tuned for the next Pulsar release!

Ran Gao
Ran Gao is a software engineer at StreamNative. Before that, he was responsible for the development of search service at Prior to that, he worked on the development of the logistics system at JD Logistics. Being interested in open source and messaging systems, Ran is an Apache Pulsar committer.
Yu Liu
Yu Liu is an Apache Pulsar PMC member and a content strategist from StreamNative.


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