We just have to pick a name for our publishing application and keep this name along the different runs.įor the publishing ID, we can use the ID of a record: it happens to be unique and the records are returned sorted by ID (e.g. Note message deduplication is not specific to the stream Java client, it can be implemented by any client as long as it complies to the semantics. The stream Java client documentation provides more details about the producer name and the publishing ID. a strictly increasing sequence value for each record, the publishing ID.We need 2 things to enable deduplication on publishing: This is when deduplication in RabbitMQ Streams comes in. With the way we implemented the application this is expected, but we have to fix this, because we just want to the new records to be published on the second run. The first 10 appears twice, so our stream contains duplicate. We see 30 messages: the 10 from the first run and the 20 from the second run. mvnw -q compile exec:java -Dexec.mainClass = '$Consume' Connecting. The publishing program mimics an application that reads records from a data source and publish a message for each a of these records: This post will start from a simple application that generates lots of duplicate messages (to help grasp the problem) and will improve it little by little to get a robust solution at the end. It is quite easy for an application to publish the same message several times: the application is restarted in the wrong way and re-publishes all the data from the beginning, a network glitch makes the application reconnect and re-send a couple of messages, etc.Įven though consuming applications should make their processing idempotent, duplicated published messages should be avoided as much as possible, as they can slow down processing and use extra space.
DEDUPLICATOR JAVA APP HOW TO
This post covers how to deduplicate published messages in RabbitMQ Streams.Īs deduplication is a critical and intricate concept, the post will walk you through this mechanism step by step, from a naive and somewhat broken publishing application to an optimized and reliable implementation. RabbitMQ Streams Overview introduced streams, a new feature in RabbitMQ 3.9 and RabbitMQ Streams First Application provided an overview of the programming model with the stream Java client.
RabbitMQ Deprecation Announcements for 4.0 » Message Deduplication with RabbitMQ Streams Tweet Follow 28, 2021
0 kommentar(er)
