Add smallrye-in-memory connector to Wildfly (Reduce redeployment time during development)

Question

During development redeploy time is critical, so it would be nice to eliminate as much as possible. In my Jakarta EE 10 .war project I connected 10 channels to Kafka topics via microprofile reactive streams. I bring up Kafka via Docker before and deploy the .war to Wildfly 28.0.1 which use smallrye-reactive-messaging. The channels are connected after the deployment is finished and this takes only a short amount of time.

But on undeployment the channels are closed synchronously one by one and the overall time is up to 10 seconds. I checked out if it is possible to reduce this time, by defining a shorter timeout or something else. But I did not find anything what can be configured here.

So my question would be if it is possible to add the smallrye-in-memory connector to Wildfly and use it during development? This would also reduce the dependency to a running Kafka during development.

Answer 1

Yes, it can be done by adding the smallrye-in-memory connector as module to Wildfly. Unfortunately there are a few steps to be done:

1. Add beans.xml to smallrye-reactive-messaging-in-memory-4.5.0.jar META-INF directory and name it smallrye-reactive-messaging-in-memory-4.5.0-beans.jar (the name is not important). This step is needed so that the io.smallrye.reactive.messaging.memory.InMemoryConnector can be injected via CDI to the io.smallrye.reactive.messaging.providers.impl.ConnectorFactories.

2. Add modules mutiny and zero-flow-adapters to Wildfly via jboss-cli.sh:

   module add --name=io.smallrye.reactive.mutiny.zero-flow-adapters --resources=mutiny-zero-flow-adapters-1.0.0.jar --dependencies=org.reactivestreams

   module add --name=io.smallrye.reactive.mutiny.zero --resources=mutiny-zero-1.0.0.jar

3. Copy smallrye-reactive-messaging-in-memory-4.5.0-beans.jar to ${WILDFLY_HOME}/modules/io/smallrye/reactive/messaging/connector/inmemory/main and create module.xml. Maybe this could be done via jboss-cli.sh but unfortunately I did not find how to specify optional and services attributes. This was the closet answer.

<module xmlns="urn:jboss:module:1.1" name="io.smallrye.reactive.messaging.connector.inmemory">

    <resources>
        <resource-root path="smallrye-reactive-messaging-in-memory-4.5.0-beans.jar"/>
    </resources>

    <dependencies>
        <module name="io.smallrye.config" services="import"/>
        <module name="io.smallrye.common.annotation"/>
        <module name="io.smallrye.reactive.converters.api"/>
        <module name="io.smallrye.reactive.messaging"/>
        <module name="io.smallrye.reactive.mutiny"/>
        <module name="io.smallrye.reactive.mutiny.reactive-streams-operators"/>
        <module name="javax.annotation.api"/>
        <module name="javax.enterprise.api"/>
        <module name="org.eclipse.microprofile.reactive-messaging.api"/>
        <module name="org.eclipse.microprofile.reactive-streams-operators.api"/>
        <module name="org.eclipse.microprofile.reactive-streams-operators.core" services="import"/>
        <module name="org.eclipse.microprofile.config.api"/>
        <module name="org.jboss.logging"/>
        <module name="org.jboss.weld.api"/>
        <module name="org.jboss.weld.core"/>
        <module name="org.jboss.weld.spi"/>
        <module name="org.reactivestreams"/>
        <module name="org.wildfly.reactive.messaging.config" optional="true" export="true" services="export"/>
        <module name="org.slf4j"/>
        <module name="io.smallrye.reactive.mutiny.zero"/>
        <module name="io.smallrye.reactive.mutiny.zero-flow-adapters"/>
    </dependencies>
</module>

3. Add io.smallrye.reactive.messaging.connector.inmemory as dependency in ${WILDFLY_HOME}/modules/system/layers/base/io/smallrye/reactive/messaging/connector/main/module.xml:

<module name="io.smallrye.reactive.messaging.connector" xmlns="urn:jboss:module:1.9">
    ...

    <dependencies>
        ...
        <module name="io.smallrye.reactive.messaging.connector.inmemory" optional="false" export="true" services="export"/>
    </dependencies>
</module>

You should now see the debug output with the found im-memory connector:

DEBUG [io.smallrye.reactive.messaging.provider] (MSC service thread 1-2) SRMSG00226: Found incoming connectors: [smallrye-in-memory, smallrye-kafka]
DEBUG [io.smallrye.reactive.messaging.provider] (MSC service thread 1-2) SRMSG00227: Found outgoing connectors: [smallrye-in-memory, smallrye-kafka]

Now you can use it in your config e.g. microprofile-config.properties:

mp.messaging.incoming.<channel>.connector=smallrye-in-memory

mp.messaging.outgoing.<channel>.connector=smallrye-in-memory

Answer 2

Kafka connector waits some grace period while closing channels to ensure that ongoing message processing and messages pending for sending are terminated.

These can be adjusted using configuration options: graceful-shutdown (true by default) for incoming channels and close-timeout (10s by default) for outgoing channels.

Hope this helps.