Jobs with large number of tasks can have job history files that are large in size and resource-consuming(mainly memory) to parse in Job History Server. If there are many such jobs, the job history server can very easily hang.
It would be a good usability feature if we added a new config property that could be set to X, where the JHS wouldn't load the details for a job with more than X tasks. The job would still show up on the list of jobs page, but clicking on it would give a warning message that the job is too big, instead of actually loading the job. This way we can prevent users from loading a job that's way too big for the JHS, which currently makes the JHS hang. The default value can be -1 so that it's disabled.