apache/druid · error · IllegalArgumentException

datasource name cannot be null

Error message

datasource name cannot be null

What it means

commitMetadataOnly() in IndexerSQLMetadataStorageCoordinator updates a supervisor's stored metadata (e.g. checkpoint offsets) inside a read-write transaction. Before opening the transaction it validates its arguments and throws IllegalArgumentException when the datasource name is null, because datasource metadata rows are keyed by the datasource and a null key is meaningless. This is a caller-side programming error, not a transient failure.

Source

Thrown at server/src/main/java/org/apache/druid/metadata/IndexerSQLMetadataStorageCoordinator.java:614

        endMetadata,
        taskAllocatorId,
        segmentSchemaMapping
    );
  }

  @Override
  public SegmentPublishResult commitMetadataOnly(
      String supervisorId,
      String dataSource,
      DataSourceMetadata startMetadata,
      DataSourceMetadata endMetadata
  )
  {
    if (supervisorId == null) {
      throw new IllegalArgumentException("supervisorId cannot be null");
    }
    if (dataSource == null) {
      throw new IllegalArgumentException("datasource name cannot be null");
    }
    if (startMetadata == null) {
      throw new IllegalArgumentException("start metadata cannot be null");
    }
    if (endMetadata == null) {
      throw new IllegalArgumentException("end metadata cannot be null");
    }

    try {
      return inReadWriteDatasourceTransaction(
          dataSource,
          transaction -> updateDataSourceMetadataInTransaction(
              transaction,
              supervisorId,
              dataSource,
              startMetadata,
              endMetadata
          )

View on GitHub (pinned to 9b90983fd2)

Solutions

1. Ensure the SupervisorSpec has a non-null dataSource before calling commitMetadataOnly.
2. Add a caller-side null/empty check on dataSource and fail fast with a descriptive message.
3. Inspect how the spec was deserialized (JSON payload missing 'dataSource') and fix the input payload or deserializer.

Example fix

// before
coordinator.commitMetadataOnly(spec.getDataSource(), spec.getId(), startMeta, endMeta);
// after
String dataSource = Preconditions.checkNotNull(spec.getDataSource(), "dataSource");
coordinator.commitMetadataOnly(dataSource, spec.getId(), startMeta, endMeta);

if (dataSource == null || dataSource.isEmpty()) {
  throw new IllegalArgumentException("dataSource must be non-null before commitMetadataOnly");
}

boolean hasDataSource(SupervisorSpec spec) { return spec.getDataSource() != null && !spec.getDataSource().isEmpty(); }

try {
  coordinator.commitMetadataOnly(dataSource, id, startMeta, endMeta);
} catch (IllegalArgumentException e) {
  log.error(e, "Supervisor metadata commit rejected: %s", e.getMessage());
}

When it happens

Trigger: Calling commitMetadataOnly(dataSource, supervisorId, startMetadata, endMetadata) with a null first argument — typically when the supervisor spec's dataSource field was never populated or was deserialized as null before the call.

Common situations: A custom supervisor implementation passes a spec whose getDataSource() returns null; external tooling invoking the coordinator directly with a partially constructed spec; unit-test code forgetting to set the datasource on a SupervisorSpec mock.

Related errors

• start metadata cannot be null
• end metadata cannot be null
• supervisorId cannot be null
• Must have a valid, non-null aggregator name
• Must have a valid, non-null aggregator name

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/2615dda951d4add2. Report an issue: GitHub.