apache/druid · error · IAE

A local input source accepts only one of %s or %s

Error message

A local input source accepts only one of %s or %s

What it means

LocalInputSourceDefn.validate permits specifying files by baseDir (optionally with filter) or by an explicit files list, but not both, since the two mechanisms are redundant and conflicting. Thrown as IllegalArgumentException when both baseDir and a non-empty files list are present.

Source

Thrown at server/src/main/java/org/apache/druid/catalog/model/table/LocalInputSourceDefn.java:102

    final boolean hasFiles = !CollectionUtils.isNullOrEmpty(CatalogUtils.safeGet(sourceMap, FILES_FIELD, List.class));
    final boolean hasFilter = !Strings.isNullOrEmpty(CatalogUtils.getString(sourceMap, FILTER_FIELD));

    if (!hasBaseDir && !hasFiles) {
      throw new IAE(
          "A local input source requires one property of %s or %s",
          BASE_DIR_FIELD,
          FILES_FIELD
      );
    }
    if (!hasBaseDir && hasFilter) {
      throw new IAE(
          "If a local input source sets property %s, it must also set property %s",
          FILTER_FIELD,
          BASE_DIR_FIELD
      );
    }
    if (hasBaseDir && hasFiles) {
      throw new IAE(
          "A local input source accepts only one of %s or %s",
          BASE_DIR_FIELD,
          FILES_FIELD
      );
    }
    super.validate(table);
  }

  @Override
  protected List<ParameterDefn> adHocTableFnParameters()
  {
    return Arrays.asList(
        new Parameter(BASE_DIR_PARAMETER, ParameterType.VARCHAR, true),
        FILTER_PARAM_DEFN,
        FILES_PARAM_DEFN
    );
  }

View on GitHub (pinned to 9b90983fd2)

Solutions

1. Remove the files list and rely on baseDir (plus optional filter)
2. Or remove baseDir/filter and keep only the explicit files list
3. Re-validate after keeping exactly one discovery mechanism

Example fix

// before
{"type":"local","baseDir":"/data","files":["/data/a.csv"]}
// after
{"type":"local","baseDir":"/data"}

if (src.containsKey("baseDir")
    && src.get("files") != null && !((List<?>) src.get("files")).isEmpty()) {
  throw new IllegalArgumentException("local source accepts baseDir or files, not both");
}

try { defn.validate(table); } catch (IAE e) { if (e.getMessage().contains("accepts only one of")) { /* remove files or baseDir */ } else { throw e; } }

When it happens

Trigger: Validating a local input source whose inputSourceMap contains a baseDir field and also a non-empty files list.

Common situations: Merging two example configs; a template that emits both keys when variables are set; incremental edits that added files without removing baseDir.

Related errors

• A local input source requires one property of %s or %s
• If a local input source sets property %s, it must also set p
• '%s' must be a string or an array of strings
• Either uri xor uriPrefix required
• Cannot define both uri and fileRegex

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/464e0628de1bbf50. Report an issue: GitHub.