RabbitMQ Message Deduplication Plugin

A plugin for filtering duplicate messages.

Messages can be deduplicated when published into an exchange or enqueued to a queue.

Installing

Download the .ez files from the chosen release and copy them into the RabbitMQ plugins directory.

Check the Release notes for minimum supported versions.

Enable the plugin:

    [sudo] rabbitmq-plugins enable rabbitmq_message_deduplication

Building from Source

Please see RabbitMQ Plugin Development guide.

To build the plugin:

    git clone https://github.com/noxdafox/rabbitmq-message-deduplication.git
    cd rabbitmq-message-deduplication
    make dist

Then copy all the *.ez files inside the plugins folder to the RabbitMQ plugins directory and enable the plugin:

    [sudo] rabbitmq-plugins enable rabbitmq_message_deduplication

Exchange level deduplication

The exchange type x-message-deduplication allows to filter message duplicates before any routing rule is applied.

Each message containing the x-deduplication-header header will not be routed if its value has been submitted previously. The amount of time a given message will be guaranteed to be unique can be controlled via the x-cache-ttl exchange argument or message header.

NOTE; This exchange acts like a fanout exchange, so routing rules are not applied.

Declare an exchange

To create a message deduplication exchange, just declare it providing the type x-message-deduplication.

Required arguments:

• x-cache-size: maximum number of entries for the deduplication cache. If the deduplication cache fills up, unspecified existing entries will be removed to give space to new ones.

Optional arguments:

• x-cache-ttl: amount of time in milliseconds duplicate headers are kept in cache.
• x-cache-persistence: whether the duplicates cache will persist on disk or in memory. Default persistence type is memory.

Message headers

• x-deduplication-header: messages will be deduplicated based on the content of this header. If the header is not provided, the message will not be checked against duplicates.
• x-cache-ttl: this header is optional and will override the default value provided during the exchange declaration. This header controls for how many milliseconds to deduplicate the message. After the TTL expires, a new message with the same header will be routed again.

Queue level deduplication

A queue declared with the x-message-deduplication parameter enabled will filter message duplicates before they are published within.

Each message containing the x-deduplication-header header will not be enqueued if another message with the same header is already present within the queue.

NOTE: Mirrored and Quorum queues are currently not supported.

Declare a queue

When declaring a queue, it is possible to enable message deduplication via the x-message-deduplication boolean argument.

Message headers

• x-deduplication-header: messages will be deduplicated based on the content of this header. If the header is not provided, the message will not be checked against duplicates.

Disabling the Plugin

It is possible to disable the plugin via the command:

    [sudo] rabbitmq-plugins disable rabbitmq_message_deduplication

All deduplication exchanges and queues will be rendered non functional. It is responsibility of the User to remove them.

Running the tests

    make tests

License

See the LICENSE file.