apache/iceberg · error · NoSuchElementException

No more scan tasks available

Error message

No more scan tasks available

What it means

Standard NoSuchElementException thrown by the FileScanTaskIterator's next() when next() is called after the iterator is exhausted. It exists to give a clearer message than the default no-args NoSuchElementException.

Solutions

  1. Guard every next() call with hasNext()
  2. Use a for-each loop instead of manual iterator calls
  3. Re-acquire the iterator (re-run tasks()) if you need to iterate again
  4. Don't store/iterate the iterator after consuming it

Example fix

// before
CloseableIterator<FileScanTask> it = tasks.iterator();
FileScanTask t1 = it.next();
FileScanTask t2 = it.next(); // throws when exhausted
// after
while (it.hasNext()) {
  FileScanTask t = it.next();
}
// or: for (FileScanTask t : tasks) { ... }
Defensive patterns

Strategy: type-guard

Validate before calling

// always check before advancing
if (iterator.hasNext()) { iterator.next(); }

Type guard

boolean safeNext(Iterator<FileScanTask> it) {
  if (!it.hasNext()) return false;
  it.next();
  return true;
}

Try / catch

try { task = it.next(); } catch (NoSuchElementException e) {
  task = null; // or break the loop
}

Prevention

When it happens

Trigger: Calling next() on a ScanTaskIterable iterator without a preceding true hasNext() — e.g. looping twice over a single-element iterator, or calling next() twice past the end.

Common situations: Bugs in code that iterates scan tasks without hasNext guards; consumer pipelines that over-advance iterators; reusing exhausted iterators instead of requesting new ones.

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/4e95e38763595c80. Report an issue: GitHub.

Appendix: source

Thrown at core/src/main/java/org/apache/iceberg/rest/ScanTaskIterable.java:270

          }
        } catch (InterruptedException e) {
          Thread.currentThread().interrupt();
          shutdown.set(true);
        }
      }

      RuntimeException workerFailure = failure.get();
      if (workerFailure != null) {
        throw workerFailure;
      }

      return hasNext;
    }

    @Override
    public FileScanTask next() {
      if (!hasNext()) {
        throw new NoSuchElementException("No more scan tasks available");
      }
      FileScanTask result = nextTask;
      nextTask = null;
      return result;
    }

    @Override
    public void close() {
      shutdown.set(true);
      LOG.info(
          "ScanTasksIterator is closing. Clearing {} queued tasks and {} plan tasks.",
          taskQueue.size(),
          planTasks.size());
      taskQueue.clear();
      planTasks.clear();
    }
  }
}

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