A job that receives as input a data stream is executed. For the job, it is iteratively determined a backlog growth over a first period of time; a backlog volume; and whether to adjust a quantity of processing resources. For each iteration for which the quantity of processing resources allocated to the job are determined to be adjusted, adjusting the quantity of processing resources allocated to the job. For each iteration for which the quantity of processing resources allocated to the job are determined not to be adjusted, maintaining the quantity of processing resources allocated to the job.