Short answer is that you dont really need one.
There's an argument called autocancel that the web interface sends to the splunk search API when a search is dispatched. The value sent is a number of seconds and Im not sure but I think we send autocancel=90 by default.
This argument says that when the search is running, if that many seconds go by without any requests to the job's assets, or without anyone hitting the /touch endpoint on the job, then the job will be cancelled.
This cancellation will not apply if either a) the job manages to finish during that time or b) someone 'saved' the results of the job or backgrounded the job, or c) some other view took over the responsibility of hitting endpoints for that running job.
That said, if that's not enough and you really dont want these unattended searches to run for even 90 seconds, there is something you can do. In the Advanced XML you can put a parameter on the <view> tag that looks like:
<view onUnloadCancelJobs="True">
And then when anyone leaves that view jobs will be explicitly cancelled EXCEPT for a) jobs that were saved by the user in that view, b) jobs that were dispatched by splunk as a part of a scheduled saved search.
I would think that simplified XML dashboards set this to True as well but I could be wrong.
