What causes "Parameter task group size is must bigger than 1." in apache/dolphinscheduler?

Pass a groupSize of at least 1 (practically the intended capacity, e.g. 10).

apache/dolphinscheduler · error · ServiceException

TASK_GROUP_SIZE_ERROR

TASK_GROUP_SIZE_ERROR

Error message

Parameter task group size is must bigger than 1.

What it means

createTaskGroup requires groupSize to be strictly positive; when groupSize <= 0 it throws ServiceException(Status.TASK_GROUP_SIZE_ERROR) with the message 'must bigger than 1'. groupSize determines how many tasks the group can hold, so a non-positive value is rejected before the duplicate-name check.

Source

Thrown at dolphinscheduler-api/src/main/java/org/apache/dolphinscheduler/api/service/impl/TaskGroupServiceImpl.java:89

    private TaskGroupQueueService taskGroupQueueService;

    @Autowired
    private ExecutorService executorService;

    @Override
    @Transactional
    public TaskGroup createTaskGroup(User loginUser, Long projectCode, String name, String description, int groupSize) {
        requireProjectPerm(loginUser, projectCode, true);
        if (checkDescriptionLength(description)) {
            log.warn("Parameter description is too long.");
            throw new ServiceException(Status.DESCRIPTION_TOO_LONG_ERROR);
        }
        if (name == null) {
            log.warn("Parameter name can ot be null.");
            throw new ServiceException(Status.NAME_NULL);
        }
        if (groupSize <= 0) {
            log.warn("Parameter task group size is must bigger than 1.");
            throw new ServiceException(Status.TASK_GROUP_SIZE_ERROR);
        }
        TaskGroup duplicate = taskGroupMapper.queryByName(loginUser.getId(), name);
        if (duplicate != null) {
            log.warn("Task group with the same name already exists, taskGroupName:{}.", duplicate.getName());
            throw new ServiceException(Status.TASK_GROUP_NAME_EXSIT);
        }
        Date now = new Date();
        TaskGroup taskGroup = TaskGroup.builder()
                .name(name)
                .projectCode(projectCode)
                .description(description)
                .groupSize(groupSize)
                .userId(loginUser.getId())
                .status(Flag.YES)
                .createTime(now)
                .updateTime(now)
                .build();

View on GitHub (pinned to 02eac45a1b)

Solutions

Pass a groupSize of at least 1 (practically the intended capacity, e.g. 10).
Default the input field to a sensible positive value instead of 0.
Clamp or reject non-positive values in the client before calling the API.
Verify the parameter key actually reaches the server (a missing int parameter binds to 0 in some binding paths).

Example fix

// before
await createTaskGroup({ name: 'etl-group', groupSize: 0 })
// after
const groupSize = Number(input.value)
await createTaskGroup({ name: 'etl-group', groupSize: Math.max(1, groupSize) })

Defensive patterns

Strategy: validation

Validate before calling

function isGroupSizeValid(size: unknown): size is number {
  return typeof size === 'number' && Number.isInteger(size) && size > 0
}
const groupSize = Number(rawInput)
if (!isGroupSizeValid(groupSize)) throw new Error('groupSize must be a positive integer')

Type guard

function isPositiveInt(v: unknown): v is number {
  return typeof v === 'number' && Number.isInteger(v) && v > 0
}

Try / catch

try {
  await createTaskGroup({ name, groupSize })
} catch (e) {
  if (isServiceException(e, 'TASK_GROUP_SIZE_ERROR')) {
    formErrors.groupSize = 'Capacity must be at least 1'
  } else throw e
}

Prevention

Use number inputs with min=1 so browsers block 0/negatives.
Coerce form strings with Number() and validate before sending (empty string coerces to 0).
Default capacity fields to a realistic positive value (e.g. 10).

When it happens

Trigger: Calling the task-group create API with groupSize=0, a negative number, or a value that binds to 0 (e.g. empty input coerced to int 0).

Common situations: UI number inputs left at default 0; scripts computing capacity as `used - free` yielding 0; int parsing of an empty string producing 0.

Understand the failure class

Background: "value must be between 0 and 1" / "out of range" / "must not be negative" errors: fixing range-validation failures across open-source libraries — this error's family across 42 libraries.

Related errors

AI-assisted analysis of apache/dolphinscheduler@02eac45a1b (2026-09-06). Data as JSON: /api/errors/c1cbe30ab2c26a6d. Report an issue: GitHub.