def _read_output(self, node_name, server, startup_event):
        while True:
            l = server.stdout.readline().decode("utf-8")
            if len(l) == 0:
                break
            l = l.rstrip()

            if l.find("Initialization Failed") != -1:
                startup_event.set()

            logger.info("%s: %s" % (node_name, l.replace("\n", "\n%s (stdout): " % node_name)))
            if l.endswith("started") and not startup_event.isSet():
                startup_event.set()
                logger.info("%s: started" % node_name)
Reads the output from the ES (node) subprocess.
dataset/ETHPy150Open elastic/rally/esrally/mechanic/launcher.py/InProcessLauncher._read_output