Chapter 3. Red Hat Decision Manager clusters in a development (authoring) environment

The primary benefit of clustering Red Hat Decision Manager development environments is high availability. If clustering is configured and Developer X is working on Node1 and that node fails, Developer X’s work is preserved and visible on any other node of the cluster.

Most development environments consist of Decision Central and at least one Decision Server .

Note

You can also use this configuration for runtime environments if you want to use Decision Central to manage the Decision Servers in the cluster.

To create a Red Hat Decision Manager clustered development environment, you download and extract Red Hat JBoss EAP 7.1 and Red Hat Decision Manager 7.1. Then, you configure Red Hat JBoss EAP 7.1 for a domain-mode cluster, including Elasticsearch and the Java messaging server (JMS) broker resource adapter integrated with Red Hat JBoss EAP. Finally, you start the cluster and install Decision Central on each cluster node.

Elasticsearch is a highly scalable open source full-text search and analytics engine. It enables you to store, search, and analyze high volumes of data quickly and in near-real time. In a Red Hat Decision Manager clustered environment, it enables you to perform complex and efficient searches across cluster nodes.

The JMS broker resource adapter enables your applications to communicate with any messaging provider. It specifies how components such as message-driven beans, Enterprise JavaBeans, and servlets can send or receive messages.

3.1. Installing and configuring Elasticsearch

To use Elasticsearch for more efficient searching across cluster nodes, you must install and configure Elasticsearch for the Red Hat Decision Manager clustered environment. Use the following instructions to configure a simplified, non-high availability environment.

To configure Elasticsearch for a high availability Red Hat Decision Manager clustered environment, see the Elasticsearch documentation.

Procedure

  1. Download and unzip the Elasticsearch installation file.
  2. Replace the contents of the elasticsearch/config/elasticsearch.yml file with the following content, where <ELASTICSEARCH_NODE_IP> is the IP address of the system where you unzipped the Elasticsearch file:

    cluster.name: kie-cluster
    transport.host: <ELASTICSEARCH_NODE_IP>
    http.host: <ELASTICSEARCH_NODE_IP>
    transport.tcp.port: 9300
    discovery.zen.minimum_master_nodes: 1
  3. Run Elasticsearch:

    • On Linux or UNIX-based systems, enter:

      ELASTICSEARCH_HOME_/bin/elasticsearch

      On Windows, enter:

      ELASTICSEARCH_HOME\bin\elasticsearch.bat

3.2. Downloading and extracting Red Hat JBoss EAP 7.1 and Red Hat Decision Manager

Complete the steps in this section to download and install Red Hat JBoss EAP 7.1 and download and repackage Red Hat Decision Manager 7.1 for installation in a clustered environment.

Procedure

  1. Install Red Hat JBoss EAP 7.1 on each node of the cluster:

    1. Navigate to the Software Downloads page in the Red Hat Customer Portal (login required), and select the product and version from the drop-down options:

      • Product: Enterprise Application Platform
      • Version: 7.1
    2. Click Download next to Red Hat JBoss Enterprise Application Platform 7.1.0. (JBEAP-7.1.0/jboss-eap-7.1.0.zip).
    3. Extract the jboss-eap-7.1.0.zip file. In the following steps, EAP_HOME is the jboss-eap-7.1/jboss-eap-7.1 directory.
  2. On the cluster node where the Red Hat JBoss EAP domain controller will be started (the master node), navigate to the Software Downloads page in the Red Hat Customer Portal, and select the product and version from the drop-down options:

    • Product: Decision Manager
    • Version: 7.1
  3. Download Red Hat Decision Manager 7.1.0 Decision Central Deployable for Red Hat JBoss EAP 7 (rhdm-7.1.0-decision-central-eap7-deployable.zip).
  4. Extract the rhdm-7.1.0-decision-central-eap7-deployable.zip file to a temporary directory. In the following commands this directory is called TEMP_DIR.
  5. Open the TEMP_DIR/rhdm-7.1.0-decision-central-eap7-deployable/jboss-eap-7.1/standalone/deployments/decision-central.war/WEB-INF/web.xml/ file, uncomment the <distributable/> tag, and save the web.xml file.
  6. Copy the contents of TEMP_DIR/rhdm-7.1.0-decision-central-eap7-deployable/jboss-eap-7.1 to EAP_HOME.
  7. Repackage the decision-central.war file:

    1. Navigate to the TEMP_DIR/rhdm-7.1.0-decision-central-eap7-deployable/jboss-eap-7.1/standalone/deployments/decision-central.war directory.
    2. Select the contents of the TEMP_DIR/rhdm-7.1.0-decision-central-eap7-deployable/jboss-eap-7.1/standalone/deployments/decision-central.war directory and create the decision-central.zip file.
    3. Rename decision-central.zip to decision-central.war. This is the file that you will use to deploy Decision Central on the cluster nodes.
    4. If desired, copy the new decision-central.war file to a location that is more convenient to deploy from.

3.3. Configuring a Red Hat JBoss EAP 7.1 domain-mode cluster for Decision Central

Configure the Decision Central cluster in domain mode with Elasticsearch and the JMS broker resource adapter integrated with Red Hat JBoss EAP. By using domain mode with a cluster, you can centrally manage and publish configurations for your servers.

Note

These steps describe a basic cluster configuration. For more complex configurations, see the Red Hat JBoss EAP 7.1 Configuration Guide.

Prerequisites

Procedure

  1. On the the master node of the cluster (where you will run the domain controller), open the EAP_HOME/domain/configuration/domain.xml file in a text editor.
  2. Make the following changes for each server group in the server-groups element:

    1. Specify the server-group name and jvm name.
    2. To enable high availability, change the profile to "full-ha" and the socket-binding-group to "full-ha-sockets".
    3. To prevent Decision Central from running out of memory, increase the JVM maximum heap size to 1500m.

      <server-group name="some-server-group" profile="full-ha">
          <jvm name="some-jvm">
              <heap size="1000m" max-size="1500m"/>
          </jvm>
          <socket-binding-group ref="full-ha-sockets"/>
      </server-group>
  3. Edit or add the following properties to the <system-properties> element and replace the following placeholders:

    • <ELASTICSEARCH_NODE_IP> is the IP addresses where Elasticseach is installed.
    • <JMS_USER> is a Red Hat JBoss EAP application user. It is the user that Decision Central uses to connect to the embedded JMS broker.
    • <JMS_USER_PASSWORD> is the password for <JMS_USER>.

      <system-properties>
        <property name="appformer-jms-connection-mode" value="JNDI"/>
        <property name="appformer-jms-username" value="<JMS_USER>  "/>
        <property name="appformer-jms-password" value="<JMS_USER_PASSWORD>"/>
        <property name="org.appformer.ext.metadata.elastic.port" value="9300"/>
        <property name="org.appformer.ext.metadata.elastic.host"
            value="<ELASTICSEARCH_NODE_IP>"/>
        <property name="org.appformer.ext.metadata.elastic.cluster"
            value="kie-cluster"/>
        <property name="org.appformer.ext.metadata.index" value="elastic"/>
        <property name="org.appformer.ext.metadata.elastic.retries" value="10"/>
        <property name="appformer-jms-connection-factory" value="java:/ConnectionFactory"/>
      </system-properties>
  4. In the <subsystem xmlns="urn:jboss:domain:messaging-activemq:2.0"> element, make the following changes:

    1. Replace <cluster password="${jboss.messaging.cluster.password:CHANGE ME!!}"/> with <cluster user="<CLUSTER_USER>" password="<CLUSTER_PWD>"/> where <CLUSTER_USER> is the user used by Red Hat JBoss EAP to form a messaging cluster and <CLUSTER_PWD> is the password for that user.
    2. In the security-setting element , add the role of the <JMS_USER> to a new role-name element, for example:

      <security-setting name="#">
          <role name="guest" send="true" consume="true" create-non-durable-queue="true" delete-non-durable-queue="true"/>
          <role name="admin" send="true" consume="true" create-non-durable-queue="true" delete-non-durable-queue="true"/>
      </security-setting>
  5. Save the domain.xml file.

3.4. Configuring Red Hat JBoss EAP 7.1 host files for a Decision Central clustered environment

After you have installed Red Hat JBoss EAP and configured the domain.xml file for a Decision Central clustered environment, complete these steps in the host.xml file on the master node and in the host-slave.xml file on each slave node.

Prerequisite

Red Hat JBoss EAP 7.1 is installed on each node of the cluster.

Procedure

  1. Open the EAP_HOME/domain/configuration/host.xml file or the EAP_HOME/domain/configuration/host-slave.xml file in a text editor.
  2. In the main-server-group <servers> element, add the servers that will be part of the cluster.
  3. Add the the system properties listed in Table 3.1, “Cluster Node Properties”
  4. Save the host.xml or host-slave.xml file.

Table 3.1. Cluster Node Properties

Property NameValueDescription

jboss.node.name

nodeOne

Node name unique within the cluster.

org.uberfire.nio.git.daemon.port

9418

Port used by the VFS repo to accept client connections. The port must be unique for each cluster member.

org.uberfire.nio.git.ssh.port

8003

The unique port number for ssh access to the Git repo for a cluster running on physical machines.

org.uberfire.nio.git.daemon.host

nodeOne

The name of the daemon host machine in a physical cluster.

org.uberfire.nio.git.ssh.host

nodeOne

The name of the SSH host machine in a physical cluster.

Example 3.1. Cluster nodeOne Configuration

<system-properties>
 <property name="jboss.node.name" value="nodeOne" boot-time="false"/>
 <property name="org.uberfire.nio.git.daemon.port" value="9418" boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.cert.dir" value="/tmp/jbpm/nodeone" boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.port" value="8003" boot-time="false"/>
 <property name="org.uberfire.nio.git.daemon.host" value="nodeOne" />
 <property name="org.uberfire.nio.git.ssh.host" value="nodeOne" />
 <property name="org.uberfire.nio.git.ssh.hostport" value="8003" boot-time="false"/>
</system-properties>

Example 3.2. Cluster nodeTwo Configuration

<system-properties>
 <property name="jboss.node.name" value="nodeTwo" boot-time="false"/>
 <property name="org.uberfire.nio.git.daemon.port" value="9418" boot-time="false"/>
           boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.cert.dir" value="/tmp/jbpm/nodetwo" boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.port" value="8003" boot-time="false"/>
 <property name="org.uberfire.nio.git.daemon.host" value="nodeTwo" />
 <property name="org.uberfire.nio.git.ssh.host" value="nodeTwo" />
 <property name="org.uberfire.nio.git.ssh.hostport" value="8003" boot-time="false"/>
</system-properties>

Example 3.3. Cluster nodeThree Configuration

<system-properties>
 <property name="jboss.node.name" value="nodeThree" boot-time="false"/>
 <property
 <property name="org.uberfire.nio.git.daemon.port" value="9418" boot-time="false"/>
           boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.cert.dir" value="/tmp/jbpm/nodethree"
           boot-time="false"/>
 <property name="org.uberfire.nio.git.ssh.port" value="8003" boot-time="false"/>
 <property name="org.uberfire.nio.git.daemon.host" value="nodeThree" />
 <property name="org.uberfire.nio.git.ssh.host" value="nodeThree" />
 <property name="org.uberfire.nio.git.ssh.hostport" value="8003" boot-time="false"/>
</system-properties>

3.5. Starting the cluster and distributing Decision Central

After you have configured a Red Hat JBoss EAP cluster and repackaged Decision Central, you must start the cluster and distribute the repackaged decision-central.war file.

Prerequisites

  • Elasticsearch is installed and running on one node of the cluster.
  • A Red Hat JBoss EAP 7.1 cluster is available and the domain.xml, host.xml, and host-slave.xml files are configured.
  • The repackaged decision-central.war file is available.

Procedure

  1. Add Red Hat JBoss EAP management users to the master node of the cluster (where you configured the domain.xml file) as described in the Red Hat JBoss EAP 7.1 Configuration Guide.
  2. On each node of the cluster, add the following users:

    1. Add Decision Central administration users as described in Installing and configuring Red Hat Decision Manager on Red Hat JBoss EAP 7.1.
    2. Add the JMS user, where <JMS_USER> and <JMS_PWD> is the JMS user and password combination that you added to the domain.xml file:

      $ ./add-user.sh -a --user <JMS_USER> --password <JMS_PWD> --role admin
  3. Start the cluster by starting the the master node first, then start each of the slave nodes.

    1. To start the master node, enter one of the following commands:

      • On Linux or UNIX-based systems, enter:

        <EAP_HOME>/bin/domain.sh
      • On Windows, enter:

        <EAP_HOME>/bin/domain.bat
    2. To start the slave nodes, on each of the slave nodes enter one of the following commands, where <MASTER_NODE_IP> is the IP address of the master node (where the domain controller is configured):

      • On Linux or UNIX-based systems, enter:

        <EAP_HOME>/bin/domain.sh --host-config=host-slave.xml -Djboss.domain.master.address=<MASTER_NODE_IP>
      • On Windows, enter:

        <EAP_HOME>/bin/domain.bat --host-config=host-slave.xml -Djboss.domain.master.address=<MASTER_NODE_IP>

        For more information, see the following sections of the Red Hat JBoss EAP 7.1 Configuration Guide:

      • "Starting JBoss EAP"
      • "Managed Domain Configuration Files"
  4. On each node of the cluster, review the EAP_HOME/domain/servers/SERVER_NAME/log/server.log file to verify that the nodes are available.
  5. To deploy the decision-central.war file into the server group, complete the following steps:

    1. On the master node, log in to the Red Hat JBoss EAP Administration console as a management user.
    2. Click Deployments → Server Groups→ main-server-group and click Add.
    3. In the dialog box, click Upload a new deployment and click Next.
    4. In the Upload Deployments dialog box, click Browse, select the decision-central.war file, and click Next.
    5. Click Enable and click Next. When the deployment is complete, Decision Central starts automatically on each node.

      Note

      Make sure to check deployment unit readiness with every cluster member.

      When a deployment unit is created on a cluster node, it takes some time before it is distributed among all cluster members. You can check the deployment status using the server Administration console or REST API. However, if the query is sent to the node where the deployment was originally issued, the query will return a value of deployed. If the query is sent to a node where the deployment has not yet been distributed, the query returns DeploymentNotFoundException.

For more information about installing Decision Central, see Installing and configuring Red Hat Decision Manager on Red Hat JBoss EAP 7.1.

3.6. Verifying the Red Hat Decision Manager cluster

After configuring the cluster for Red Hat Decision Manager, create an asset to verify that the installation is working.

Procedure

  1. In a web browser, enter <node-IP-address>:8080/decision-central. Replace <node-IP-address> with the IP address of a particular node.
  2. Enter the admin user credentials that you created during installation. The Decision Central home page appears.
  3. Select MenuDesignProjects.
  4. Click Try SamplesMortgagesOK. The Assets window appears.
  5. Click Create New AssetData Object.
  6. Enter MyDataObject in the Data Object field and click OK.
  7. Click SpacesmyteamMortgages and confirm that MyDataObject is in the list of assets.
  8. Enter the following URL in a web browser, where <node_IP_address> is the address of a different node of the cluster:

    http://<node_IP_address>:8080/decision-central

  9. Enter the same credentials that you used to log in to Decision Central on the first node, where you created the MyDataObject asset.
  10. Select MenuDesignProjects.
  11. Select the Mortgages project.
  12. Verify that MyDataObject is in the asset list.
  13. Delete the Mortgages project.