private function killKeepTransactionAlive() {
        if ($this->txProcPid > 0) {
            posix_kill($this->txProcPid, \SIGKILL);
            $status          = null;
            pcntl_wait($status);
            $this->txProcPid = null;
        }
        if ($this->txProc) {
            $this->txProc = null;
        }
    }