apache/flink · error · IllegalArgumentException

The cpu cores and task heap memory are required when specify

Error message

The cpu cores and task heap memory are required when specifying the resource of a slot sharing group. You need to explicitly configure them with positive value.

What it means

SlotSharingGroup.Builder.build() enforces an all-or-nothing rule: either all required resource fields are set (cpuCores AND taskHeapMemory are mandatory; others optional) producing a resource-annotated group, or none are set producing a name-only group. Setting any resource field while cpuCores or taskHeapMemory is null throws this IllegalArgumentException.

Source

Thrown at flink-core-api/src/main/java/org/apache/flink/api/common/SlotSharingGroup.java:229

        /** Build the SlotSharingGroup. */
        public SlotSharingGroup build() {
            if (cpuCores != null && taskHeapMemory != null) {
                taskOffHeapMemory = Optional.ofNullable(taskOffHeapMemory).orElse(MemorySize.ZERO);
                managedMemory = Optional.ofNullable(managedMemory).orElse(MemorySize.ZERO);
                return new SlotSharingGroup(
                        name,
                        cpuCores,
                        taskHeapMemory,
                        taskOffHeapMemory,
                        managedMemory,
                        externalResources);
            } else if (cpuCores != null
                    || taskHeapMemory != null
                    || taskOffHeapMemory != null
                    || managedMemory != null
                    || !externalResources.isEmpty()) {
                throw new IllegalArgumentException(
                        "The cpu cores and task heap memory are required when specifying the resource of a slot sharing group. "
                                + "You need to explicitly configure them with positive value.");
            } else {
                return new SlotSharingGroup(name);
            }
        }
    }
}

View on GitHub (pinned to 2f3c205e92)

Solutions

1. Add the missing mandatory values: always pair setCpuCores(...) with setTaskHeapMemory(...) (or the MB overload).
2. If you do not want resource annotations, remove ALL resource setters and build a name-only group.
3. Centralize group construction in one factory that either sets the full mandatory pair plus optionals, or none.

Example fix

// before
SlotSharingGroup.newBuilder("g")
    .setTaskOffHeapMemory(MemorySize.ofMebiBytes(64))
    .build(); // throws: cpuCores/taskHeapMemory missing

// after
SlotSharingGroup.newBuilder("g")
    .setCpuCores(1.0)
    .setTaskHeapMemoryMB(256)
    .setTaskOffHeapMemory(MemorySize.ofMebiBytes(64))
    .build();

boolean anyResource = cpuCores != null || taskHeap != null || offHeap != null || managed != null || !ext.isEmpty();
boolean mandatory = cpuCores != null && taskHeap != null;
if (anyResource && !mandatory) throw new IllegalStateException("Set both setCpuCores and setTaskHeapMemory, or no resource at all");

When it happens

Trigger: Calling build() after setting e.g. setManagedMemory(...) or setTaskOffHeapMemory(...) but omitting setCpuCores or setTaskHeapMemory; or setting only setCpuCores without heap memory.

Common situations: Incrementally migrating config to fine-grained resource management and setting only managed/off-heap memory; templated builders where some setters are conditional and the mandatory pair is skipped.

Related errors

• The cpu cores should be positive.
• At least one trigger condition must be configured.
• The task heap memory should be positive.
• The jarFile and entryPointClassName can not be null at the s
• Not allowed configuration change(s) were detected:\n - {erro

AI-assisted analysis of apache/flink@2f3c205e92 (2026-08-14). Data as JSON: /api/errors/6c5d74d42bf9d767. Report an issue: GitHub.