apache/iceberg · warning

Table does not have a UUID, this may cause issues with…

Error message

Table {} does not have a UUID, this may cause issues with commit coordination on table replace

What it means

IcebergWriterFactory.createWriter logs a warning when table.uuid() returns null, meaning the catalog could not supply a stable table UUID. The UUID is used to build a TableReference that lets Kafka Connect's commit coordination detect when a table was replaced/renamed between writes; without it, a table replace can go undetected and commits may target the wrong table metadata.

Solutions

1. Upgrade the catalog implementation/Iceberg version so TableMetadata carries a UUID
2. Check why table.uuid() is null for your catalog — ensure the catalog returns real TableMetadata, not a wrapped/stubbed Table
3. If the warning is benign (commits never span table replaces), suppress or ignore it and monitor for misdirected commits
4. Set the table's uuid explicitly by rewriting table metadata with the current Iceberg core writer

Example fix

// before
Table table = customCatalog.loadTable(identifier);
return new IcebergWriter(table, TableReference.of(catalog.name(), identifier, table.uuid()), config);
// after
// use a catalog that supplies uuid, e.g. HiveCatalog/HadoopCatalog upgraded to a version that populates TableMetadata.uuid

if (table.uuid() == null) { LOG.warn("table {} has no uuid; commit coordination on replace will be unreliable", identifier); }

boolean hasUuid(Table t) { return t.uuid() != null; }

When it happens

Trigger: Instantiating an IcebergWriter via createWriter against a catalog whose Table implementation does not expose a UUID (e.g. custom or older catalog implementations, or tables resolved through wrappers that drop the uuid field).

Common situations: Using a custom Catalog implementation that does not set the uuid in its TableMetadata; serializing/deserializing Table objects that lose the uuid; older Iceberg catalog builds where uuid was optional.

Related errors

• An error occurred closing catalog instance, ignoring...
• Cannot convert to UUID
• Commit failed for task ( consecutive failures, will retry)
• Table not found, skipping commit
• Altering a view is not supported by catalog:

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/437c4d29ccabff54. Report an issue: GitHub.

Appendix: source

Thrown at kafka-connect/kafka-connect/src/main/java/org/apache/iceberg/connect/data/IcebergWriterFactory.java:74

  RecordWriter createWriter(String tableName, SinkRecord sample, boolean ignoreMissingTable) {
    TableIdentifier identifier = TableIdentifier.parse(tableName);
    Table table;
    try {
      table = catalog.loadTable(identifier);
    } catch (NoSuchTableException nst) {
      if (config.autoCreateEnabled()) {
        table = autoCreateTable(tableName, sample);
      } else if (ignoreMissingTable) {
        return new NoOpWriter();
      } else {
        throw nst;
      }
    }

    UUID tableUuid = table.uuid();
    if (tableUuid == null) {
      LOG.warn(
          "Table {} does not have a UUID, this may cause issues with commit coordination on table replace",
          identifier);
    }
    TableReference tableReference = TableReference.of(catalog.name(), identifier, tableUuid);

    return new IcebergWriter(table, tableReference, config);
  }

  @VisibleForTesting
  Table autoCreateTable(String tableName, SinkRecord sample) {
    StructType structType;
    if (sample.valueSchema() == null) {
      Type type = SchemaUtils.inferIcebergType(sample.value(), config);
      if (type == null) {
        throw new DataException("Unable to create table from empty object");
      }
      structType = type.asStructType();
    } else {

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