Fix MQTTv5 reconnection race condition #10705
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Fixes: spring-projects#10697 Address race condition in `Mqttv5PahoMessageHandler` when multiple threads attempt to connect simultaneously. Changes: - Add `RetryTemplate` with configurable retry count for connection attempts - Implement `MqttExceptionMatcher` to handle specific MQTT error codes - Add `setRetryConnectionCount` method to configure retry behavior - Create test suite validating retry logic The retry mechanism specifically handles `REASON_CODE_CONNECT_IN_PROGRESS` and `REASON_CODE_CLIENT_CONNECTED` errors, allowing the client to recover gracefully when connection establishment is already in progress. Default retry count is set to 5 with 100ms delay between attempts.
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Good. I’ll take a look into your idea in the morning. Meanwhile , please , check this where we give a retry option already: https://docs.spring.io/spring-integration/reference/handler-advice.html |
Enhance `Mqttv5PahoMessageHandler` to support custom `RetryTemplate` configuration for connection retry logic. Previously, the retry behavior was hardcoded with a fixed policy. Users can now provide their own `RetryTemplate` for more flexible retry strategies. Changes: - Add `connectionRetryTemplate` field to store custom retry template - Add `setConnectionRetryTemplate` setter for configuration - Initialize `connectionRetryTemplate` in `onInit` if not already set - Rename `getRetryTemplate` to `getDefaultConnectionRetryTemplate` - Update Javadoc for `setRetryConnectionCount` to note custom template takes precedence - Remove NOSONAR comment from token wait call
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Good point. I thought about allowing the user set the retry policy but thought it was overkill. But after your comment above, I reconsidered and added that capability. |
Provide a lightweight while to check for connection vs heavyweight retrytemplate
artembilan
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Jan 15, 2026
...src/test/java/org/springframework/integration/mqtt/Mqttv5ReconnectionRaceConditionTests.java
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...src/test/java/org/springframework/integration/mqtt/Mqttv5ReconnectionRaceConditionTests.java
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...src/test/java/org/springframework/integration/mqtt/Mqttv5ReconnectionRaceConditionTests.java
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...src/test/java/org/springframework/integration/mqtt/Mqttv5ReconnectionRaceConditionTests.java
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...tt/src/main/java/org/springframework/integration/mqtt/outbound/Mqttv5PahoMessageHandler.java
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* It assumed multi-thread issue which is not always correct * Update documentation to remove multi-thread connection association * Cleanup based on code review
artembilan
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Jan 15, 2026
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Will merge when build is green
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Fixes: #10697
Address race condition in
Mqttv5PahoMessageHandlerwhen multiple threads attempt to connect simultaneously.Changes:
RetryTemplatewith configurable retry count for connection attemptsMqttExceptionMatcherto handle specific MQTT error codessetRetryConnectionCountmethod to configure retry behaviorThe retry mechanism specifically handles
REASON_CODE_CONNECT_IN_PROGRESSandREASON_CODE_CLIENT_CONNECTEDerrors, allowing the client to recover gracefully when connection establishment is already in progress. Default retry count is set to 5 with 100ms delay between attempts.