hashicorp/nomad · error

failed updating variable index: %w

Error message

failed updating variable index: %w

What it means

After inserting the variable, updateVarsAndIndexTxn updates the table's IndexEntry (TableVariables -> idx) so blocking queries see the new version. This error wraps tx.Insert into tableIndex failing. The variable insert was already performed in the same transaction, but since the function returns early the transaction aborts and the whole write is rolled back.

Source

Thrown at nomad/state/state_store_variables.go:582

	if err != nil {
		req.ErrorResponse(idx, fmt.Errorf("failed lock release: %s", err))
	}

	if err := tx.Commit(); err != nil {
		return req.ErrorResponse(idx, err)
	}

	return req.SuccessResponse(idx, &updated.VariableMetadata)
}

func (s *StateStore) updateVarsAndIndexTxn(tx WriteTxn, idx uint64, sv *structs.VariableEncrypted) error {
	if err := tx.Insert(TableVariables, sv); err != nil {
		return fmt.Errorf("failed inserting variable: %w", err)
	}

	if err := tx.Insert(tableIndex,
		&IndexEntry{TableVariables, idx}); err != nil {
		return fmt.Errorf("failed updating variable index: %w", err)
	}
	return nil
}

func isLocked(lock *structs.VariableLock, req *structs.VarApplyStateRequest) bool {
	if lock != nil {
		if req.Var.VariableMetadata.Lock == nil ||
			req.Var.VariableMetadata.Lock.ID != lock.ID {

			return true
		}
	}
	return false
}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Check the wrapped cause and server logs; verify disk space and health of the Nomad data_dir.
2. Restart the server to rebuild state; restore from snapshot if corruption is detected.
3. Retry the operation; the aborted transaction leaves state consistent at the previous index.

func isVarIndexUpdateFailure(err error) bool { return err != nil && strings.Contains(err.Error(), "failed updating variable index") }

if err := applyVariable(op); err != nil {
  if isVarIndexUpdateFailure(err) {
    // whole txn aborted; state is consistent at previous index
    return retryWithBackoff(op)
  }
  return err
}

When it happens

Trigger: tx.Insert(tableIndex, &IndexEntry{TableVariables, idx}) fails while committing any variable mutation (apply, lock release) in the FSM state store.

Common situations: Same storage-layer failures as variable insert: disk-full data_dir, BoltDB errors, memory pressure; rarely seen in isolation on a healthy server.

Related errors

• failed to retrieve jobs for idempotency check
• failed to lookup state snapshot: %v
• node lookup failed: %v
• node update failed: %v
• volume update failed: %s: %v

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/3debddd10ef4e04c. Report an issue: GitHub.