In order to work in cluster mode, you must have previously set up high availability on your system. Below is a list of the main concepts associated with clustering:
High availability is a design approach that ensures a level of operational continuity and minimises the risk of unplanned downtime. It is achieved through load balancing and failover.
High availability with Talend refers only to the scheduling of task executions.
Load balancing allows you to distribute work across the clustered Web servers. It is often combined with failover.
Failover allows you to automatically switch to a standby server if the primary server is down or temporarily unreachable. For example, if a request to run a Job is sent to a server that is unreachable, it is automatically redirected to the backup server which will perform the desired operation.