Comparison
Quality of service classvsResource request
Quality of service class
the workload with no requests set was the first one killed when the node ran out of memory, and nobody had chosen that.
A classification the platform derives from your requests and limits, which decides the order things are killed under pressure: equal requests and limits are protected, requests below limits are burstable, neither set is expendable. It is not a field you set, it is a consequence of two fields you did set, which is why teams are surprised by their own ranking. Anything whose loss would be an incident should be in the protected class deliberately.
Full entry →Resource request
you promise the scheduler the workload needs half a core, and that half core is subtracted from the node whether or not you ever use it.
The amount of CPU and memory a workload reserves, used by the scheduler to decide which nodes can hold it. It is a claim on capacity rather than a cap on usage, which is the distinction almost everyone gets wrong first. Requests set far above real usage are how a cluster ends up at thirty percent utilisation and a full bin at the same time, and requests set far below are how a node ends up oversubscribed and thrashing.
Full entry →