apache/druid · error · org.apache.druid.java.util.common.IAE

Unable to create storage connector

Error message

Unable to create storage connector [%s] for base path [%s]

What it means

LocalFileExportStorageProvider.createStorageConnector builds a LocalFileStorageConnector for the validated export destination; if constructing it (creating directories/paths) raises IOException, it is rethrown as IAE stating the connector class and base path. It means the local export directory could not be initialized.

Solutions

1. Verify druid.export.storage.baseDir exists, is a directory, and is writable by the Druid process (mkdir/chown as needed).
2. Ensure the export path does not collide with an existing regular file.
3. Check container/mount permissions and SELinux policies for the export directory.
4. Retry the export after fixing permissions; inspect the chained IOException cause for the exact filesystem error.

Example fix

// before
File dir = new File("/mnt/export"); // read-only mount
// after
File dir = new File("/mnt/export");
if (!dir.isDirectory() || !dir.canWrite()) {
  throw new IOException("export base dir not writable: " + dir);
}
dir.setWritable(true);

File dir = new File(baseDir);
if (!dir.isDirectory() || !dir.canWrite()) throw new IOException("export base dir invalid or unwritable: " + dir);

try { connector = provider.createStorageConnector(config); } catch (IllegalArgumentException e) { throw new RuntimeException("check export baseDir permissions/path: " + e.getMessage(), e); }

When it happens

Trigger: Export query with destination whose validated base path cannot be turned into a connector: unable to create the directory, permission denied, path is an existing non-writable file, invalid path characters.

Common situations: druid.export.storage.baseDir pointing to a read-only mount; export path overlapping a file instead of a directory; container without write access to configured export dir; NFS permission issues.

Understand the failure class

Background: "Permission denied" / "Failed to write" file errors: why a library can't write its files to disk (EACCES, EPERM, ENOSPC) and how to fix them — this error's family across 43 libraries.

Related errors

• Found a directory on path
• Invalid arguments for reading
• No directory exists on path
• Unable to find file for reading

AI-assisted analysis of apache/druid@9b90983fd2 (2026-09-07). Data as JSON: /api/errors/7000adebbbc188ad. Report an issue: GitHub.

Appendix: source

Thrown at processing/src/main/java/org/apache/druid/storage/local/LocalFileExportStorageProvider.java:64

  @JsonProperty
  private final String exportPath;

  @JsonCreator
  public LocalFileExportStorageProvider(@JsonProperty(value = "exportPath", required = true) String exportPath)
  {
    this.exportPath = exportPath;
  }

  @Override
  public StorageConnector createStorageConnector(File taskTempDir)
  {
    final File exportDestination = validateAndGetPath(storageConfig.getBaseDir(), exportPath);
    try {
      return new LocalFileStorageConnector(exportDestination);
    }
    catch (IOException e) {
      throw new IAE(
          e,
          "Unable to create storage connector [%s] for base path [%s]",
          LocalFileStorageConnector.class.getSimpleName(),
          exportDestination.toPath()
      );
    }
  }

  @Override
  @JsonIgnore
  public String getResourceType()
  {
    return TYPE_NAME;
  }

  @Override
  @JsonIgnore
  public String getBasePath()

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