Enable "max_process_steps_per_task" for API jobs in a job chain

Current Situation

• When using an API job in a job chain then a running task of this job ends only after a idle time (default 5 seconds). If another order starts the job while a task of this job is still running (within the idle time) then the same task is used.
• This behaviour provides a better performance but it can caus problems if too many orders are processed in the same task:
  • The loaded JVM in the task can get a OutOfMemoryError
  • The task log is too large for writing into the database history.

Desired Behavior

• An attribute "max_process_steps_per_task" is available that causes JobScheduler to terminate and restart the task after the specified number of process steps for API jobs.

Delimitation

• This attribute has no effect for standalone jobs.
• This attribute has no effect for shell jobs in a job chain. Such jobs always use one process step per task.