import httplib import os import time def check_http(i):     try:         conn=httplib.HTTPConnection(i, 80, timeout=2)         conn.request("GET","/")         response = conn.getresponse()     except Exception as e:         print "server "+i+" is down"         print e         print ""         os.system('./delete_real_server.sh '+i)     else:         #print response.read()         print "server "+i+" is upn"         os.system('./add_real.server.sh '+i)         if __name__=="__main__":     httpservers=["127.0.0.1","10.0.0.1","192.168.35.28"]     while 1:         current_time=time.strftime('%Y-%m-%d %H:%M:%S',time.localtime(time.time()))         for i in httpservers:             check_http(i)         print current_time+" check finishn"         time.sleep(60)