To implement this High Availability architecture, you need first to install and configure several instances of the application server and connect them to the project administration database.
Install Tomcat in cluster mode
Install one Tomcat server as described in Deploying Talend Administration Center on an application server.
Before starting Tomcat and deploying Talend Administration Center, set it into cluster mode. To do so:
Edit the following file:
Uncomment the following lines by removing the hash character preceding the command :
#org.quartz.scheduler.instanceName = MyClusteredScheduler
#org.quartz.scheduler.instanceId = AUTO
#org.quartz.jobStore.isClustered = true
#org.quartz.jobStore.clusterCheckinInterval = 20000
Duplicate Tomcat and the TAC web application
Duplicate this Tomcat instance on different servers, as many times as needed.
Make sure that all system clocks are synchronized (the clocks must be within a second of each other). For more information on time-sync services, please refer to the appropriate Microsoft documentation about SNTP, Windows Time Service tools and Network Clocks.
Duplicate the org.talend.administrator Web application to all Tomcat instances. Make sure that all Web application configurations are identical.
Launch one Tomcat instance following the commands given at the end of Deploying Talend Administration Center on an application server.
Launch the other instances of Tomcat following the same procedure.
Fail-over will occur when one of the multiple execution servers fails while in the midst of executing one or more tasks. When a server fails, the other servers of the cluster detect the condition and identify the tasks in the database that were in progress within the failed server. Any tasks marked for recovery will be taken over by another server.
Note that the ranking of servers to be used for load balancing is based on indicators, whose
bounds (such as free disk space limits) and weight are defined in the file:
monitoring_client.properties which is located in <ApplicationPath>\WEB-INF\lib\org.talend.monitoring.client-A.B.C.jar.
These values can be edited according to your needs. For more information, see Configuring the indicators which determine which server to be used for load
You can also deploy Talend Administration Center on a JBoss application server (instead of a Tomcat). So, you can follow the same above instructions for Jboss. For more information on how to deploy the Web application on JBoss, see Deploying Talend Administration Center on JBoss.
One known minor issue related to the DST change might prevent the failover to operate properly. However as a simple workaround, simply restart Tomcat after the time change. This should have no impact on executions.