apache/pulsar · error · IllegalArgumentException

Per instance CPU requested is not specified. Must specify CP

Error message

Per instance CPU requested is not specified. Must specify CPU requested for function to be at least %s

What it means

validateMinResourcesRequired enforces a worker-configured minimum CPU per function instance. If functionInstanceMinResources.cpu is set but the submitted function has no Resources section at all, Pulsar throws IllegalArgumentException telling the user to specify CPU at least equal to the configured minimum.

Source

Thrown at pulsar-functions/runtime/src/main/java/org/apache/pulsar/functions/runtime/kubernetes/KubernetesRuntimeFactory.java:449

            if (data.containsKey(field.getName()) && !data.get(field.getName())
                    .equals(field.get(kubernetesRuntimeFactory))) {
                log.info().attr("field", field.getName())
                        .attr("oldValue", field.get(kubernetesRuntimeFactory))
                        .attr("newValue", data.get(field.getName()))
                        .log("Kubernetes Config changed");
                field.set(kubernetesRuntimeFactory, data.get(field.getName()));
            }
        }
    }

    void validateMinResourcesRequired(FunctionDetails functionDetails) {
        if (functionInstanceMinResources != null) {
            Double minCpu = functionInstanceMinResources.getCpu();
            Long minRam = functionInstanceMinResources.getRam();

            if (minCpu != null) {
                if (!functionDetails.hasResources()) {
                    throw new IllegalArgumentException(
                            String.format("Per instance CPU requested is not specified. "
                                    + "Must specify CPU requested for function to be at least %s", minCpu));
                } else if (functionDetails.getResources().getCpu() < minCpu) {
                    throw new IllegalArgumentException(
                            String.format("Per instance CPU requested, %s, "
                                            + "for function is less than the minimum required, %s",
                                    functionDetails.getResources().getCpu(), minCpu));
                }
            }

            if (minRam != null) {
                if (!functionDetails.hasResources()) {
                    throw new IllegalArgumentException(
                            String.format("Per instance RAM requested is not specified. "
                                    + "Must specify RAM requested for function to be at least %s", minRam));
                } else if (functionDetails.getResources().getRam() < minRam) {
                    throw new IllegalArgumentException(
                            String.format("Per instance RAM requested, %s, "

View on GitHub (pinned to 820761864e)

Solutions

Add --cpu <value> (>= configured minimum) to the function create/update command.
Set resources.cpu in the FunctionDetails config (or functionConfig yaml) before submission.
Ask the cluster admin to lower functionInstanceMinResources.cpu if the minimum is too strict.
Pre-validate resources in your deployment pipeline against the worker config before calling the admin API.

Example fix

// before
pulsar-admin functions create --name f --inputs t ...
// after
pulsar-admin functions create --name f --inputs t --cpu 0.5 ...

Defensive patterns

Strategy: validation

Validate before calling

Resources res = config.getResources();
Double minCpu = workerCfg.getFunctionInstanceMinResources().getCpu();
if (minCpu != null && (res == null || !res.isSetCpu())) {
    throw new IllegalArgumentException("--cpu is required and must be >= " + minCpu);
}

Try / catch

try { admin.functions().createFunction(config); } catch (IllegalArgumentException e) { if (e.getMessage().contains("CPU requested is not specified")) { config.setResources(...); } throw e; }

Prevention

Always pass --cpu when creating functions on Kubernetes runtime
Mirror the worker's min-resources config in your deployment tooling defaults
Review functions_worker.yml min resources after cluster upgrades

When it happens

Trigger: Submitting a function without --cpu (no functionDetails.resources) while the worker has functionInstanceMinResources.cpu configured (doAdmissionChecks -> validateMinResourcesRequired, line 449).

Common situations: New cluster hardening that introduced minimum resource settings while existing function-submit pipelines omit resources; migrating functions from a cluster without minimums; defaults stripped by automation tooling.

Related errors

AI-assisted analysis of apache/pulsar@820761864e (2026-09-06). Data as JSON: /api/errors/1c56c7dc4b6abed0. Report an issue: GitHub.