Reduce the number of request for getting job data
At the moment the number of such requests several times more than the number of all other requests taken together. Moreover, the most of them are useless since they are made just to check whether a job status changes while it changes very-very seldom. I suppose to increase the request period like schedulers already do for updating statuses for jobs and tasks. Say, you can request a job status each 5 seconds during 1 minute, then each 10 seconds during another minute, then each 20 seconds during another minute and so on.