apache/hadoop · error · IllegalArgumentException

Failed to invoke getSnapshotDiffReport.

Error message

Failed to invoke getSnapshotDiffReport.

What it means

Error "Failed to invoke getSnapshotDiffReport." thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-distcp/src/main/java/org/apache/hadoop/tools/DistCpSync.java:327

        "getSnapshotDiffReport", Path.class, String.class, String.class);
  }

  /**
   * Get the snapshotDiff b/w the fromSnapshot & toSnapshot for the given
   * filesystem.
   */
  private static SnapshotDiffReport getSnapshotDiffReport(
      final FileSystem fs,
      final Path snapshotDir,
      final String fromSnapshot,
      final String toSnapshot) throws IOException {
    try {
      return (SnapshotDiffReport) getSnapshotDiffReportMethod(fs).invoke(
          fs, snapshotDir, fromSnapshot, toSnapshot);
    } catch (InvocationTargetException e) {
      throw new IOException(e.getCause());
    } catch (NoSuchMethodException|IllegalAccessException e) {
      throw new IllegalArgumentException(
          "Failed to invoke getSnapshotDiffReport.", e);
    }
  }

  private String getSnapshotName(String name) {
    return Path.CUR_DIR.equals(name) ? "" : name;
  }

  private Path getSnapshotPath(Path inputDir, String snapshotName) {
    if (Path.CUR_DIR.equals(snapshotName)) {
      return inputDir;
    } else {
      return new Path(inputDir,
          HdfsConstants.DOT_SNAPSHOT_DIR + Path.SEPARATOR + snapshotName);
    }
  }

  private Path createTargetTmpDir(FileSystem targetFs,

View on GitHub (pinned to 2add963021)

Solutions

1. Check NameNode logs and permissions for snapshot diff on the directory.
2. Verify both snapshots exist and the caller has access.
3. Retry; transient RPC failures can cause this.

When it happens

Trigger: The getSnapshotDiffReport RPC fails during distcp sync.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/b9260fef2b6a3e7c. Report an issue: GitHub.