Introduction

The JS7 - Agent Cluster brings horizontal scalability and fail-over capabilities for Agents.

• A number of Subagents operated for different servers share the job execution load in an Agent Cluster (active-active cluster).
• Automated fail-over guarantees high availability and restart capabilities of an Agent Cluster (active-passive cluster).

The JS7 offers a number of clustering options:

• An Agent Cluster can be operated with a Standalone JOC Cockpit and with a JS7 - JOC Cockpit Cluster.
• An Agent Cluster can be operated with a Standalone Controller and with a JS7 - Controller Cluster.

Operation of an Agent Cluster is subject to the JS7 - License and is available to commercial license holders.

In this article you find step-by-step instructions for setup of an Agent Cluster, for full explanations refer to the JS7 - Agent Management article.

Prerequisites

The following requirements have to be met before setting up an Agent Cluster:

• The JOC Cockpit should be up & running and accessible from your browser, see JS7 - Initial Operation for JOC Cockpit Cluster.
• The Controller should be up & running, see JS7 - Initial Operation for Controller Cluster.
• A JS7 License Key is required for JOC Cockpit and for the Controller independently from the fact that the components are operated standalone or in a cluster, see JS7 - How to apply a JS7 License Key.

Set up Agent Cluster

1. Login to the JOC Cockpit and navigate to the Manage Controllers/Agents view from the  Administration icon.
   
   
   
   
2. The page displays existing Standalone Agents and Cluster Agents:
   
   
   
   
3. To add a new Agent Cluster click the Controller's action menu and click the Add Agent Cluster menu item:
   
   
   
   
4. A popup window will appear to add an Agent Cluster:
   
   
   • Fill out mandatory input fields: Agent ID and Agent Name of the Agent Cluster.
     • The Agent ID is a unique string that identifies the Agent Cluster and that cannot be changed later on.
     • The Agent Name is a unique string that identifies the Agent Cluster and that can be changed later on.
   • Add the Primary Director Agent with its Subagent ID and URL.
     • The Primary Director Agent works as an interface between Controller and Subagents in a cluster.
     • The Primary Director Agent manages the Agent Cluster and distributes orders to Subagents. Preferably it is not used for job execution.
     • The Subagent ID is a unique string that identifies the Primary Director Agent and that cannot be changed later on.
     • The URL specifies the protocol, host and port for which the Primary Director Agent is available.
   • The Secondary Director Agent is used as a fallback should the Primary Director Agent not be available.
     FEATURE AVAILABILITY STARTING FROM RELEASE 2.5.0

     
     

     
     
     
     
     

Add SubAgents

1. After submitting the Agent Cluster add a number of Subagents. Click the action menu of the recently created Agent Cluster and click the Add Subagent menu item:
   
   
   
   
2. A popup window will appear. Add the Subagent ID and the URL.
   
   
   • The Subagent ID is a unique string that identifies the Subagent and cannot be changed later.
   • The URL specifies the protocol, host, and port for which the Subagent is available.
     
     
     
     
3. Repeat the above steps to add a number of more Subagents to the Agent Cluster.
4. In this example, two Subagents are added to the Agent Cluster.
   
   
   
   
5. Once all Subagents are added then select the Agent Cluster action menu and click the Deploy menu item.
   
   
   
   
6. After successfully deploying the cluster Agent the status will be changed to the synchronized state.
   
   
   
   

Add Subagent Cluster

1. To add a Subagent Cluster select the Agent Cluster action menu and click the Manage Subagent Cluster menu item.
   
   
   
   
2. A new window will appear with the list of Cluster Agents click on any of the cluster Agents.
   
   
   
   
3. This brings up the following popup window:
   • In the left panel, the list of Subagents is available and can be dragged & dropped to the middle panel.
   • The middle panel holds a drop area to which a Subagent can be dragged & dropped.
     
     
     
     
4. The Primary Director Agent is already added to the graphical view for the adding the first Subagent to the cluster the middle panel offers additional drag & drop areas:
   • The next Subagent can be dropped to the area above the existing Subagent to specify its role as the first Subagent used with the fixed-priority scheduling mode.
     • In this mode, the first Subagent is used; only if it becomes unavailable will the next Subagent be used.
       
       
       
       
   • The next Subagent can be dropped to the area below the existing Subagent to specify its roles as the next Subagent used with the fixed-priority scheduling mode.
     • In this mode, the next Subagent is used only if the first Subagent becomes unavailable.
   • The next Subagent can be dropped to the area right to the existing Subagent to specify the use of the round-robin scheduling mode.
     • In this mode, each next task is executed with the next Subagent.
       
       

5. Once the configuration of a Subagent Cluster is completed the cluster can be deployed to its Controller.

   • A Subagent Cluster can be used only after deployment to a Controller.
   • Changes to a Subagent Cluster require to be deployed, for example, if a Subagent is added or removed from a cluster.
   • Deployment of Subagent Clusters can be performed individually and from bulk operations, see chapter: Bulk Operations on Subagent Clusters.
   • When deploying an Agent Cluster then this includes deploying any available Subagent Clusters, see chapter: Deploy Agent Cluster.

   
   

6. To Deploy the Agent cluster to its controller click on the Deploy button from the upper right corner.
   
   
   
   
7. After a successful deployment of the Agent cluster, each Subagent Cluster is individually assigned to a job.
   • The property editor offers to select from the list of Agents that can be assigned a job.
     • This includes Standalone Agents.
     • This includes Subagent Clusters that are grouped by Agent Cluster.
   • Assignment of Subagent Clusters can look like this: