Introduction

• The Agent Cluster brings fail-over capabilities and horizontal scalability to Agents.
• FEATURE AVAILABILITY STARTING FROM RELEASE 2.2.0

Architecture

Explanation:

• An Agent Cluster consists of two Agent Directors and a number of Subagents.

Agent Director

Each Agent Director ships with a Subagent that is running inside the Director.

• The Subagent can be instructed to execute tasks by the active Director that it is operated for. This can be the Subagent's Director or a remote Director. 
• It is an option to disable the Director's Subagent in order to have the Director perform orchestration only and not to execute jobs.

Journal

Each Agent Director holds a journal to store events about JS7 - Order State Transitions and to store log output reported from Subagents executing jobs.

The journal is essential for the restart capability of an Agent Directory.

If the Agent Director is operated as a cluster then the active Director synchronizes its journal with the standby Director. When both journals of active and standby Directors are in synch then a fail-over (automatically) or switch-over (caused by user intervention) can occur and the Directors switch roles of the active and standby instance.

Sharing of Duties

A number of JS7 - Workflow Instructions, for example Retry, Try/Catch, Fork - are performed by 

Subagent

Subagents can be operated individually

Sharing of Duties

• JOC Cockpit holds the configuration for any number of
  • Standalone Controllers and Controller Clusters including
    • URLs of Controller instances
  • Standalone Agents and Agent Clusters including
    • Agent Director URLs and Subagent URLs
    • assignment of Subagents to an Agent Cluster
• The Controller

The Controller holds the configuration