the id of the task is unique (https://github.com/droolsjbpm/jbpm/blob/master/jbpm-human-task/src/main/java/org/jbpm/task/Task.java), you cannot have two tasks with the same task id.
Maybe you are confusing it with the node id?
Maybe i'm confusing, for me, the taskid is the number associate with an task in a process definition (the value that we set in properties in the eclipse editor).
If my vision about taskid is correct, when we insert a process definition to the knowledge base, a special logic to verify if there are id conflict wasnt necessary ?
Well, this is not the real task id. This is a node id internally used in the process definition.
The task id refers to an instance of a human task, and it will be unique in the task service..
Hope this helps,
Thanks for the help.