Not familiar with gearman or that module but from skimming the docs and code my take is that's a timeout for hearing a response back from asking gearman to start something as opposed to a timeout on the work you’re asking it to do. Terrrible analogy follows which may not be even relevant; but my impression is that it's kind of like the difference between expecting your waiter to take your order promptly (the command timeout) and how long it takes the kitchen to actually make the order once the waiter delivers it (a timeout on the job itself).