apache/beam · error · IllegalArgumentException

Attempting to call and() on a CoGbkResult apparently not cre

Error message

Attempting to call and() on a CoGbkResult apparently not created by of().

What it means

CoGbkResult.and() is only valid on results created via CoGbkResult.of(), which track nextTestUnionId as they grow. Calling and() on a result constructed directly with the constructor (or after repeated and() calls beyond the schema) breaks that invariant and is rejected.

Source

Thrown at sdks/java/core/src/main/java/org/apache/beam/sdk/transforms/join/CoGbkResult.java:362

  }

  //////////////////////////////////////////////////////////////////////////////
  // Methods for directly constructing a CoGbkResult
  //
  // (for example, creating test data for a transform that consumes a
  // CoGbkResult)

  /** Returns a new CoGbkResult that contains just the given tag and given data. */
  public static <V> CoGbkResult of(TupleTag<V> tag, List<V> data) {
    return CoGbkResult.empty().and(tag, data);
  }

  /**
   * Returns a new {@link CoGbkResult} based on this, with the given tag and given data added to it.
   */
  public <V> CoGbkResult and(TupleTag<V> tag, List<V> data) {
    if (nextTestUnionId != schema.size()) {
      throw new IllegalArgumentException(
          "Attempting to call and() on a CoGbkResult apparently not created by" + " of().");
    }
    List<Iterable<?>> valueMap = new ArrayList<>(this.valueMap);
    valueMap.add(data);
    return new CoGbkResult(
        new CoGbkResultSchema(schema.getTupleTagList().and(tag)), valueMap, nextTestUnionId + 1);
  }

  /** Returns an empty {@link CoGbkResult}. */
  public static CoGbkResult empty() {
    return new CoGbkResult(
        new CoGbkResultSchema(TupleTagList.empty()), new ArrayList<Iterable<?>>());
  }

  //////////////////////////////////////////////////////////////////////////////

  private int nextTestUnionId = 0;

View on GitHub (pinned to 12126d8942)

Solutions

Build results with CoGbkResult.of(tupleTagList, rawResults) and use and() from there
If you must append, construct the CoGbkResult yourself with the extended TupleTagList and full valueMap instead of chaining and()
Verify nextTestUnionId equals schema.size() before calling and()

Example fix

// before
CoGbkResult r = new CoGbkResult(schema, valueMap, 0);
r = r.and(tag, data); // throws
// after
CoGbkResult r = CoGbkResult.of(tagList.and(tag), rawValueMap);

Defensive patterns

Strategy: type-guard

Validate before calling

if (nextTestUnionId != schema.size()) { throw new IllegalStateException("Use CoGbkResult.of() before and()"); }

Try / catch

try { return result.and(tag, data); } catch (IllegalArgumentException e) { throw new IllegalStateException("CoGbkResult not created via of()", e); }

Prevention

Always use CoGbkResult.of() factory methods
Avoid direct constructor use in user code
Track and() call counts against schema size in tests

When it happens

Trigger: Calling and() on a CoGbkResult created with new CoGbkResult(schema, valueMap, nextUnionId) where nextTestUnionId != schema.size(), or chaining and() more times than the base schema allows.

Common situations: Custom pipeline code constructing CoGbkResult instances manually for testing or deserialization and then trying to append tags; framework-internal results (e.g. from raw union decoding) being mutated.

Understand the failure class

Background: "Invalid state transition" errors: "status must be X, actually Y", "already rejected/charging/uninstalled", "cannot ... while running" — what they mean when a library rejects your call — this error's family across 31 libraries.

Related errors

AI-assisted analysis of apache/beam@12126d8942 (2026-09-13). Data as JSON: /api/errors/883f3f5b2f1e78ff. Report an issue: GitHub.