How to configure JBoss / WildFly deployment order

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You can configure JBoss EAP / WildFly deployment order in some simple steps. This article will show you how to do it!

Configuring Deployment order within an EAR file

If you want to deploy applications within an EAR file with a precise order, then you can use the element named initialize-in-order (available in application.xml 6.0 schema). This element, if set to true, initializes the modules in the same order they are listed. For example here the webapp.war will be initialized as first module of the ear:

<?xml version="1.0" encoding="UTF-8"?>
<application xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  version="6" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/application_6.xsd">
 
  <application-name>sampleapp</application-name>
  <initialize-in-order>true</initialize-in-order>
  <module>
    <web>
      <web-uri>webapp.war</web-uri>
      <context-root>test</context-root>
    </web>
  </module>
 
  <module>
    <ejb>core-ejb.jar</ejb>
  </module>

</application>

On the other hand, here is another example if you are using the https://jakarta.ee namespace in application.xml:

<?xml version="1.0" encoding="UTF-8"?>

<application xmlns="https://jakarta.ee/xml/ns/jakartaee"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="https://jakarta.ee/xml/ns/jakartaee https://jakarta.ee/xml/ns/jakartaee/application_10.xsd"
             version="10">

    <initialize-in-order>true</initialize-in-order>

    <module>
        <web>
            <web-uri>sample.war</web-uri>
            <context-root>sample</context-root>
        </web>
    </module>

    <module>
        <ejb>hello.jar</ejb>
    </module>

</application>

Configuring deployment order between multiple deployments

What if you need configuring the deployment order between two applications, say two EAR files ? then you can use jboss-deployment-structure.xml.  This file is a WildFly specific deployment descriptor that you can use to control class loading in a fine grained manner. You should place it in the top level deployment, in META-INF (or WEB-INF for web deployments).

For example, let’s say you have app1.ear and app2.ear. Here we configured the deployment structure of app2.ear to depend on app1.ear, so that the former will be deployed first:

<?xml version="1.0" encoding="UTF-8"?>
<jboss-deployment-structure>
   <deployment>
       <dependencies>
           <module name="deployment.app1.ear" />
       </dependencies>
   </deployment>
</jboss-deployment-structure>

Important! If you need to configure a dependency toward one or more EAR files, which are deployed separately, then you need to use jboss-all.xml file as follows:

<jboss umlns="urn:jboss:1.0">
    <jboss-deployment-dependencies xmlns="urn:jboss:deployment-dependencies:1.0">
        <dependency name="application1.ear" />
        <dependency name="application2.ear" />
    </jboss-deployment-dependencies>
</jboss>

For more examples of jboss-deployment-structure.xml check this article: Examples of jboss-deployment-structure.xml

Configuring deployment with the CLI

Finally, it’s worth mentioning you can use JBoss / WildFly CLI to deploy applications using a strict order. Simply use the “deploy” command which will deploy the single applications. Then, wait to complete before moving to the next command.

Besides it, if you wrap the deployment within a batch command, you will have a guarantee that, should one deployment fail, there will be a rollback of deployed applications:

batch
deploy /tmp/app1.war
deploy /tmp/app2.war
run-batch
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