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MOP v4.0.4.3 latest startup error with pulsar 4.0.4

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
35/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
java
Domain
backend, networking

Research direction

Reproduce the issue with Pulsar 4.0.4, the MOP v4.0.4.3 NAR, and bin/pulsar standalone. Start at MQTTService.java:118 and MQTTProtocolHandler.java:97 in the stack trace, then inspect how the protocol handler is packaged and loaded; done means Pulsar starts without the NoClassDefFoundError.

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Description

Describe the bug
MOP v4.0.4.3 latest startup error with pulsar 4.0.4

To Reproduce
1.pulsar 4.0.4 download url https://downloads.apache.org/pulsar/pulsar-4.0.4/apache-pulsar-4.0.4-bin.tar.gz
2. mop download url https://github.com/streamnative/mop/releases/download/v4.0.4.3/pulsar-protocol-handler-mqtt-4.0.4.3.nar
2. config mop with url https://github.com/streamnative/mop/releases/download/v4.0.4.3/pulsar-protocol-handler-mqtt-readme.md
3. startup pulsar with command line: bin/pulsar standalone
5. See error
Expected behavior
2025-06-16T14:49:12,347+0800 [pulsar-17-2] INFO org.apache.pulsar.broker.PulsarService - Loading all topics on bundle: pulsar/127.0.0.1:8080/0x00000000_0xffffffff
2025-06-16T14:49:12,357+0800 [main] ERROR org.apache.pulsar.PulsarStandaloneStarter - Failed to start pulsar service.
java.lang.NoClassDefFoundError: io/netty/handler/codec/mqtt/MqttMessage
at io.streamnative.pulsar.handlers.mqtt.broker.MQTTService.(MQTTService.java:118) ~[?:?]
at io.streamnative.pulsar.handlers.mqtt.broker.MQTTProtocolHandler.start(MQTTProtocolHandler.java:97) ~[?:?]
at org.apache.pulsar.broker.protocol.ProtocolHandlerWithClassLoader.start(ProtocolHandlerWithClassLoader.java:93) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at org.apache.pulsar.broker.protocol.ProtocolHandlers.lambda$start$4(ProtocolHandlers.java:153) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at java.base/java.lang.Iterable.forEach(Iterable.java:75) ~[?:?]
at org.apache.pulsar.broker.protocol.ProtocolHandlers.start(ProtocolHandlers.java:153) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at org.apache.pulsar.broker.PulsarService.start(PulsarService.java:1048) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at org.apache.pulsar.PulsarStandalone.start(PulsarStandalone.java:354) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at org.apache.pulsar.PulsarStandaloneStarter.start(PulsarStandaloneStarter.java:122) ~[org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]
at org.apache.pulsar.PulsarStandaloneStarter.main(PulsarStandaloneStarter.java:179) [org.apache.pulsar-pulsar-broker-4.0.4.jar:4.0.4]

Desktop (please complete the following information):

  • OS: macOS Sequoia 15.5

Additional context
JDK version:
java version "17.0.11" 2024-04-16 LTS
Java(TM) SE Runtime Environment (build 17.0.11+7-LTS-207)
Java HotSpot(TM) 64-Bit Server VM (build 17.0.11+7-LTS-207, mixed mode, sharing)

Dominant language
Java
Stars
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Forks
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