What causes "Failed to list all reachable files" in apache/iceberg?

Read the logged cause; fix the underlying storage/metadata problem.

Failed to list all reachable files

Error message

Failed to list all reachable files

What it means

At the end of ReachableFileCleanup.findFilesToDelete, any Throwable escaping the per-manifest Tasks blocks is caught, logged with this warning, and an empty set of files-to-delete is returned. This makes snapshot expiration fail-safe: if reachable-file enumeration cannot be completed, no files are deleted rather than risking data loss.

Solutions

Read the logged cause; fix the underlying storage/metadata problem.
Re-run expireSnapshots — the empty result means nothing was deleted, so it is safe to retry.
For very large tables, expire incrementally (expire older snapshots in batches) to reduce resource pressure.
Restore/rewrite table metadata with RewriteTablePathUtil if paths are broken.

Defensive patterns

Strategy: fallback

Validate before calling

// pre-validate all metadata readability before expiring
SnapshotsUtil.sortedSnapshots(table).forEach(s ->
    table.io().newInputFile(s.manifestListLocation()).exists());

Try / catch

// the library already falls back to an empty set; treat empty filesToDelete as 'nothing expired'
if (result.filesDeleted() == 0 && result.filesToDeleteCount() > 0) { /* investigate and retry */ }

Prevention

Check storage health before running expiration
Expire snapshots incrementally on very large tables
Never assume expiration deleted files; verify the returned metrics

When it happens

Trigger: Any unrecoverable exception during reachable file enumeration during expireSnapshots — RuntimeIOException from unreadable manifests/manifest lists, storage outages, or unexpected runtime errors while reading paths.

Common situations: Prolonged object-store outages, credentials revoked mid-job, corrupt metadata from a broken table copy, and OOM/other runtime errors on very large tables during expiration.

Understand the failure class

Background: EmptyResultError / "no results found": when an API or scraper succeeds but returns zero rows — this error's family across 9 libraries.

Related errors

AI-assisted analysis of apache/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/4d79f63ef5894bf8. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/apache/iceberg/ReachableFileCleanup.java:224

                  LOG.warn(
                      "Failed to determine live files in manifest {}. Retrying", item.path(), exc))
          .run(
              manifest -> {
                if (filesToDelete.isEmpty()) {
                  return;
                }

                // Remove all the live files from the candidate deletion set
                try (CloseableIterable<String> paths =
                    ManifestFiles.readPaths(manifest, fileIO, specsById)) {
                  paths.forEach(filesToDelete::remove);
                } catch (IOException e) {
                  throw new RuntimeIOException(e, "Failed to read manifest file: %s", manifest);
                }
              });

    } catch (Throwable e) {
      LOG.warn("Failed to list all reachable files", e);
      return Sets.newHashSet();
    }

    return filesToDelete;
  }
}

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