apache/iceberg · error · CherrypickAncestorCommitException

Cannot cherrypick snapshot %s: already picked to create ance

Error message

Cannot cherrypick snapshot %s: already picked to create ancestor %s

What it means

Cherry-picking a snapshot requires that the snapshot was not already cherry-picked into the current table's history. CherryPickOperation.validate() checks whether the snapshot is a current ancestor, or whether a previously cherry-picked copy of it already exists as an ancestor (via the source-snapshot-id metadata). Throwing prevents duplicating changes already in the ancestor lineage.

Source

Thrown at core/src/main/java/org/apache/iceberg/CherryPickOperation.java:214

          isFastForward,
          "Cannot cherry-pick snapshot %s: not append, dynamic overwrite, or fast-forward",
          cherrypickSnapshot.snapshotId());
      return base.snapshot(cherrypickSnapshot.snapshotId());
    } else {
      // validate(TableMetadata) is called in apply(TableMetadata) after this apply refreshes the
      // table state
      return super.apply();
    }
  }

  private static void validateNonAncestor(TableMetadata meta, long snapshotId) {
    if (isCurrentAncestor(meta, snapshotId)) {
      throw new CherrypickAncestorCommitException(snapshotId);
    }

    Long ancestorId = lookupAncestorBySourceSnapshot(meta, snapshotId);
    if (ancestorId != null) {
      throw new CherrypickAncestorCommitException(snapshotId, ancestorId);
    }
  }

  private static void validateReplacedPartitions(
      TableMetadata meta, Long parentId, PartitionSet replacedPartitions, FileIO io) {
    if (replacedPartitions != null && meta.currentSnapshot() != null) {
      ValidationException.check(
          parentId == null || isCurrentAncestor(meta, parentId),
          "Cannot cherry-pick overwrite, based on non-ancestor of the current state: %s",
          parentId);
      List<Snapshot> snapshots =
          Lists.newArrayList(
              SnapshotUtil.ancestorsBetween(
                  meta.currentSnapshot().snapshotId(), parentId, meta::snapshot));
      if (!snapshots.isEmpty()) {
        Iterable<CloseableIterable<DataFile>> addedFileTasks =
            Iterables.concat(
                Iterables.transform(

View on GitHub (pinned to 86d9c8fc54)

Solutions

Do not cherry-pick the same snapshot twice; check ancestry before calling cherryPick.
Inspect the exception's createAncestorId to find the existing commit and confirm the change is already applied.
If you intentionally want the change again, create a new snapshot (re-write or re-commit) rather than re-picking.
Fast-forward/rollback the target branch instead of cherry-picking if the intent is to reach the source state.

Example fix

// before
table.cherryPick(snapshotId); // may already be picked
// after
if (!SnapshotUtil.currentAncestorIds(table).contains(snapshotId)) {
  table.cherryPick(snapshotId);
}

Defensive patterns

Strategy: validation

Validate before calling

List<Long> ancestors = SnapshotUtil.currentAncestorIds(table);
if (ancestors.contains(snapshotId)) {
  throw new IllegalStateException("snapshot already picked: " + snapshotId);
}

Prevention

Track which snapshots have been cherry-picked in your pipeline state.
Make cherry-pick operations idempotent at the application level.
Check for CherrypickAncestorCommitException and treat it as already-applied.

When it happens

Trigger: Calling table.cherryPick(snapshotId) where snapshotId is already an ancestor of the current snapshot, or where an earlier cherry-pick of the same source snapshot produced an ancestor commit.

Common situations: Re-running a cherry-pick operation after a prior successful run; scripted retry logic that re-invokes cherryPick on the same snapshot id; applying a branch snapshot that was already picked into main.

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/iceberg@86d9c8fc54 (2026-09-12). Data as JSON: /api/errors/8e3d299ea4e6329e. Report an issue: GitHub.