apache/hadoop · error · UnsupportedOperationException

{} doesn't support getAllStoragePolicies

Error message

{} doesn't support getAllStoragePolicies

What it means

AbstractFileSystem.getAllStoragePolicies() is a default stub that throws UnsupportedOperationException naming the subclass. Enumerating the storage-policy catalog is HDFS-only; through FileContext any other resolved implementation fails with this error before returning a collection.

Source

Thrown at hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java:1572

   * @param src file or directory path.
   * @return storage policy for give file.
   * @throws IOException raised on errors performing I/O.
   */
  public BlockStoragePolicySpi getStoragePolicy(final Path src)
      throws IOException {
    throw new UnsupportedOperationException(getClass().getSimpleName()
        + " doesn't support getStoragePolicy");
  }

  /**
   * Retrieve all the storage policies supported by this file system.
   *
   * @return all storage policies supported by this filesystem.
   * @throws IOException raised on errors performing I/O.
   */
  public Collection<? extends BlockStoragePolicySpi> getAllStoragePolicies()
      throws IOException {
    throw new UnsupportedOperationException(getClass().getSimpleName()
        + " doesn't support getAllStoragePolicies");
  }

  @Override //Object
  public int hashCode() {
    return myUri.hashCode();
  }
  
  @Override //Object
  public boolean equals(Object other) {
    if (!(other instanceof AbstractFileSystem)) {
      return false;
    }
    return myUri.equals(((AbstractFileSystem) other).myUri);
  }

  /**
   * Open a file with the given set of options.

View on GitHub (pinned to 2add963021)

Solutions

  1. Call getAllStoragePolicies only on hdfs:// filesystems.
  2. Use DistributedFileSystem.getAllStoragePolicies or `hdfs dfsadmin -listStoragePolicies`.
  3. Probe once at startup, catch UnsupportedOperationException, and cache "policies unavailable" for that filesystem.
  4. Default to an empty policy list in UIs when the backend has no policy engine.

Example fix

// before
Collection<? extends BlockStoragePolicySpi> ps = fc.getAllStoragePolicies();

// after
Collection<? extends BlockStoragePolicySpi> ps;
try {
  ps = fc.getAllStoragePolicies();
} catch (UnsupportedOperationException e) {
  ps = Collections.emptyList();
}
Defensive patterns

Strategy: try-catch

Validate before calling

static boolean policyOpsSupported(Path p) {
  return "hdfs".equals(p.toUri().getScheme());
}

Try / catch

try {
  policies = fc.getAllStoragePolicies();
} catch (UnsupportedOperationException e) {
  policies = Collections.emptyList();
}

Prevention

When it happens

Trigger: FileContext.getAllStoragePolicies() on local or object-store filesystems; tools that populate a policy dropdown/list from the filesystem (like `hdfs dfsadmin -listStoragePolicies` but via the generic API) pointed at a non-HDFS defaultFS.

Common situations: Cluster-management or UI code enumerating policies on connect, executed in tests with file://; a client configured for the wrong endpoint (s3a endpoint URL) where the code assumed HDFS.

Related errors

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/230ef959752549e1. Report an issue: GitHub.