Introduction

• The outage of an Agent will stop the execution of workflows with that Agent. Workflows running with Agents that remain available are unaffected.
• Workflows that miss their scheduled execution date will be executed when the Agent becomes available.

Controller Behavior

• The Controller is used at design-time to deploy workflows and to submit orders to Agents. At run-time the Controller receives information about execution results and order state transitions from Agents.
• If an Agent becomes unavailable then
  • the Controller will try to reconnect to the respective Agent.
  • the Controller reports the missing Agent connection to the JOC Cockpit.
• When the connection to the Agent is re-established then the Controller continues receipt of execution results and order state transitions.

JOC Cockpit Behavior

• JOC Cockpit receives information about Agents from a Controller. There is no direct connection to an Agent.
• In case of outage of an Agent
  • the Controller reports the information to JOC Cockpit that will display the missing Agent connection with its Dashboard.
  • any interaction with an Agent such as deployment of workflows or requests for submission/cancellation of orders to that Agent are delayed. The Controller accepts such requests and will forward them to the Agent when the Agent becomes available. It is therefore not required to repeat such requests as they are promised to be executed on availability of an Agent.

Agent Behavior

The agent is the component in JS7 that executes the workflow and stores all the information in the form of journals and pass the results to the Controller. The outage of the agent affects the execution of the workflows. The workflow will not be executed if the agent is not available. But will execute all the outstanding orders whenever the agent is available.

The agent outage can be handled either by resolving the issue with the current agent (by restarting) or by moving the /state directory to the running agent. The journals for the agent are stored in the /state directory. So if we want the workflow execution of one agent to be forwarded to another agent then we need to copy the journals of the unavailable agent to another agent.

So, if agent1 is facing the outage and the agent2 is running (on the same server or another server) then follow the below steps to forward the execution of orders from agent1 to agent2:

1.  Shutdown the services of agent2
2. Copy the files from the state folder of agent1 to the state folder of agent2. 
3. Start the services of agent2
4. If the agent URL is the same for agent2 then the orders will be automatically started. But if the agent URL is changed then it has to be updated in the JOC Cockpit.
5. To change the agent URL, login to the JOC Cockpit.
6. From the profile select Manage Controllers/Agents.
7. Make sure you edit the existing agent which is not in service as if we add a new agent then all the workflows need to be updated with the new Agent. So, edit the agent which is not available due to the outage.
8. Change the agent1 URL to the agent2 URL and click Submit button:
   
   
   
   

Note: If required to copy the journals from agent2 to agent1 once the agent1 is available otherwise the Controller will not be able to couple with the Agent

The SOS has performed the successful test with the scenario when the Agent was not available for 24 hours and we copied the files from the state folder of agent1 to agent2. Changed the URL in the JOC Cockpit for the Agent. Then the agent2 executed all the outstanding orders from the previous day and also the new orders.