# Motivation There are many users who need to use tag messages. The implementation of this part has also been discussed before：
https://lists.apache.org/list.html?*@pulsar.apache.org:lte=2y:Proposal%20for%20Consumer%20Filtering%20in%20Pulsar%20brokers I suggest to plug-in the Dispatcher, so that users can not only develop tag messages, but also customize their own delayed messages and other features. Plug-in Dispatcher has no compatibility impact on existing Brokers. # Modifications 1. Add a configuration item `dispatcherProviderClassName`，the creation of an existing Dispatcher will be moved to DefaultDispatcherProvider, as the default class. 2. Add a new Interface DispatcherProvider public interface DispatcherProvider { // Use `DispatcherProvider` to create `Dispatcher` Dispatcher createDispatcher(Consumer consumer, Subscription subscription); static DispatcherProvider createDispatcherProvider(ServiceConfiguration serviceConfiguration) { // According to `dispatcherProviderClassName`, create Provider through reflection } } We can get BrokerService from Subscription, and then Pulsar from BrokerService, so the parameters of this interface must be sufficient. DispatcherProvider will be created when the subscription is initialized: ``` DispatcherProvider.createDispatcherProvider(config); ``` When there is a Consumer subscription, we will create a Dispatcher: dispatcher = dispatcherProvider.createDispatcher(consumer, this); I opened a new PR： https://github.com/apache/pulsar/pull/11948
