hashicorp/nomad · error

failed inserting variable: %w

Error message

failed inserting variable: %w

What it means

updateVarsAndIndexTxn inserts the VariableEncrypted object into the variables table within the active write transaction. This error wraps tx.Insert failing for the variable entry itself, aborting the whole update (variable + index) since it returns early. Callers like VarLockRelease and VarApply propagate it up as the RPC error response.

Source

Thrown at nomad/state/state_store_variables.go:577

	updated := sv.Copy()
	updated.Lock = nil
	updated.ModifyIndex = idx

	err = s.updateVarsAndIndexTxn(tx, idx, &updated)
	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. Read the wrapped %w cause; if it mentions BoltDB/IO, check data_dir disk space and permissions.
2. Restart the Nomad server process to rebuild the in-memory state from disk.
3. Restore from a valid snapshot if the store is corrupted.
4. Retry the variable write; the failed txn was fully rolled back so nothing is half-written.

Example fix

// before
if err := client.State().SetVariable(sv); err != nil { panic(err) }
// after
if err := client.State().SetVariable(sv); err != nil {
  if strings.Contains(err.Error(), "failed inserting variable") {
    logger.Error("variable write rejected by state store", "path", sv.Path, "err", err)
  }
}

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

if err := applyVariable(op); err != nil {
  if isVarInsertFailure(err) {
    logger.Error("variable write rolled back", "path", op.Var.Path, "err", err)
    return retryWithBackoff(op)
  }
  return err
}

When it happens

Trigger: tx.Insert(TableVariables, sv) returns an error during any variable write (create/update/lock release) applied to the state store.

Common situations: BoltDB write failures from disk-full, permission problems on data_dir, or memory pressure in the memdb layer on large variables; seen after unclean shutdowns leaving the store in a bad state.

Related errors

• failed to retrieve jobs for idempotency check
• variable doesn't exist
• variable doesn't hold a lock
• failed to lookup state snapshot: %v
• node lookup failed: %v

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/1a70be2cbb71f5ff. Report an issue: GitHub.