Description of problem:
When trying to do several tasks at the same time, it is likely that some of them are stuck (i..e candlepin synchronization tasks).
There should be another way of cancelling tasks

Version-Release number of selected component (if applicable):

6.0.8
How reproducible:
Often happens with first time syncronization

Steps to Reproduce:
1. Install satellite, including manifest
2. Synchronize several products at the same time (i.e. RHEL 6+ RHEL7 + RHEV+ CloudForms+ OpenStack)
3. See tasks are in error state, stopped or pending

Actual results:
Trying to kill some tasks in the console, either foreman or dynaflow, does not work. Following steps in https://access.redhat.com/comment/913073#comment-913073?sc_cid=cp|emnt|sol|cmt& does not work either

Expected results:
Task should be cleaned and cancelled.
A visual clue should be added to show the customer that some tasks are running, including tasks in error with dependencies (thus no other tasks can proceed)
A visual clue should be added when adding new tasks ("There are tasks pending in error state for "pulp", it is possible that your task has to wait for the previous tasks to finish or be cancelled)
hammer should include a way to show all tasks, including those who are stopped, paused, and in error state
When choosing several tasks to cancel,  you should be able to choose them with a single click (after a search)
You should be able to force a task to be cancelled, even if you offer the opportunity to do it again (cancel --> does not work --> force cancellation --> [option to reset it and start it again])


Additional info: