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Mission / Euler CPU
04 / 0530 active minutesshared compute

Cap And Calculate Euler Job Arrays

You can add an explicit concurrency cap, validate one representative task, calculate aggregate resources across overlapping submissions, and cancel failed or duplicate arrays.

Work herelocal / powershell or zsh or bash
  1. 1Understand
  2. 2Do
  3. 3Check
  4. 4Submit
Learn firstConcept, example, trap and recovery

Outcome#

You can add an explicit concurrency cap, validate one representative task, calculate aggregate resources across overlapping submissions, and cancel failed or duplicate arrays.

Concept#

Array size is not concurrency. An uncapped array can make many tasks eligible simultaneously, and several individually capped arrays can still exceed a safe aggregate request.

Worked Example#

The deterministic parser accepts the bounded array and no command submits it to Euler.

A correct example uses these decisions:

  • What does %4 mean in --array=0-31%4? At most four array tasks may run concurrently.
  • Which placeholders distinguish array logs? %A for the parent job and %a for the task index.

Common Trap#

Submitting a large array before adding %N, or using %j so tasks overwrite or obscure one another.

If Blocked#

Reduce the cap to %1 and validate a representative input. If many tasks fail identically, cancel the array and debug one task. Use the job arrays lab for dependent or heterogeneous workloads.

Useful references:

Understand Before Accepting AI Output#

Calculate concurrency yourself and include other submissions. A personal or lab limit is a ceiling, not a target for an agent to consume.

Do the mission

One bounded attempt

Pass: 100% + every safety item
Action

Correct the supplied Slurm array fixture so it has an explicit % concurrency cap and unique parent/task log names.

Expected

The deterministic parser accepts the bounded array and no command submits it to Euler.

Separate practice space

Open this mission's safe practice files

The launcher creates or validates a separate exercise folder. It stops rather than replacing an existing unrelated folder.

01What does %4 mean in --array=0-31%4?Safety-critical
02Which placeholders distinguish array logs?
Before submitting

The launcher will copy only this mission's declared synthetic practice files into the public submission. Review those files as well as these answers.

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