A box of workers that knows when to ask for help

Each batch of photos has a deadline. The box predicts the work from the image sizes, hands it out ten images at a time to whichever task is due first, and turns away what it cannot finish. Below that, you can let the naive version run the box for a minute and watch what happens when workers that fall behind call helpers, who call helpers.

Workers busy

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Tasks in the queue

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Images per second

0.0

Reconnecting to the box…

What the box is doing

Waiting for something to happen.

Let a splitting policy run the box

For a minute the pool steps aside and a policy that gives each task its own workers takes over, with tasks arriving at 1.2 times what the box can do. Workers that fall behind call helpers. Everything runs inside the box's limits: 1.5 CPUs, 1.5 GB, 35 processes.

The boxSplits once a task is past its deadline. No budget, no depth limit. This is the one that falls over.Forecast, no budgetSplits when the projected finish is past the deadline. Depth and fan-out limits, nothing global.Forecast, with a budgetThe same forecast inside a budget of two workers, with admission control and a breaker.Forecast, with preemptionAlso splits into idle workers and makes the latest deadline yield. The closest a splitting policy gets to the pool.

A box of workers that knows when to ask for help

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What the box is doing

Let a splitting policy run the box