TestON/tests/HATestZK/HATestZK.py

'''
Description: This case is to ensure that in the event of Zookeeper failures (including the leader node)
the cluster should continue to function properly by the passing of Zookeeper functionality to the 
remaining nodes. In this test, a quorum of the Zookeeper instances must be kept alive.

'''
class HATestZK:

    global topology
    global masterSwitchList
    global highIntentList
    global lowIntentList
    global flows
    flows = []

    def __init__(self) :
        self.default = ''

    '''
    CASE1 is to close any existing instances of ONOS, clean out the 
    RAMCloud database, and start up ONOS instances. 
    '''
    def CASE1(self,main) :
        main.case("Initial Startup")
        main.step("Stop ONOS")
        main.ONOS1.stop_all()
        main.ONOS2.stop_all()
        main.ONOS3.stop_all()
        main.ONOS4.stop_all()
        main.ONOS5.stop_all()
        main.ONOS1.stop_rest()
        main.ONOS2.stop_rest()
        main.ONOS3.stop_rest()
        main.ONOS4.stop_rest()
        main.ONOS5.stop_rest()
        result = main.ONOS1.status() or main.ONOS2.status() \
                or main.ONOS3.status() or main.ONOS4.status() or main.ONOS5.status()
        utilities.assert_equals(expect=main.FALSE,actual=result,onpass="ONOS stopped successfully",onfail="ONOS WAS NOT KILLED PROPERLY")
        main.step("Startup Zookeeper")
        main.ZK1.start()
        main.ZK2.start()
        main.ZK3.start()
        main.ZK4.start()
        main.ZK5.start()
        result = main.ZK1.isup() and main.ZK2.isup()\
                and main.ZK3.isup() and main.ZK4.isup() and main.ZK5.isup()
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Zookeeper started successfully",onfail="ZOOKEEPER FAILED TO START")
        main.step("Cleaning RC Database and Starting All")
        main.RC1.del_db()
        main.RC2.del_db()
        main.RC3.del_db()
        main.RC4.del_db()
        main.RC5.del_db()
        main.ONOS1.start_all()
        main.ONOS2.start_all()
        main.ONOS3.start_all()
        main.ONOS4.start_all()
        main.ONOS5.start_all()
       # main.ONOS1.start_rest()
        main.step("Testing Startup")
        result1 = main.ONOS1.rest_status()
        vm1 = main.RC1.status_coor and main.RC1.status_serv and \
                main.ONOS1.isup()
        vm2 = main.RC2.status_coor and main.ONOS2.isup()
        vm3 = main.RC3.status_coor and main.ONOS3.isup()
        vm4 = main.RC4.status_coor and main.ONOS4.isup()
        vm5 = main.RC5.status_coor and main.ONOS5.isup()
        result = result1 and vm1 and vm2 and vm3 and vm4 and vm5
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Everything started successfully",onfail="EVERYTHING FAILED TO START")
        if result==main.FALSE:
            main.cleanup()
            main.exit()

    '''
    CASE2
    '''
    def CASE2(self,main) :
        import time
        import json
        import re
        main.log.report("Assigning Controllers")
        main.case("Assigning Controllers")
        main.step("Assign Master Controllers")
        for i in range(1,29):
            if i ==1:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip1'],port1=main.params['CTRL']['port1'])
            elif i>=2 and i<5:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip2'],port1=main.params['CTRL']['port2'])
            elif i>=5 and i<8:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip3'],port1=main.params['CTRL']['port3'])
            elif i>=8 and i<18:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip4'],port1=main.params['CTRL']['port4'])
            elif i>=18 and i<28:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip5'],port1=main.params['CTRL']['port5'])
            else:
                main.Mininet1.assign_sw_controller(sw=str(i),ip1=main.params['CTRL']['ip1'],port1=main.params['CTRL']['port1'])
        
        result = main.TRUE
        for i in range (1,29):
            if i==1:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is " + str(response))
                if re.search("tcp:"+main.params['CTRL']['ip1'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE
            elif i>=2 and i<5:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is " + str(response))
                if re.search("tcp:"+main.params['CTRL']['ip2'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE
            elif i>=5 and i<8:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is " + str(response))
                if re.search("tcp:"+main.params['CTRL']['ip3'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE
            elif i>=8 and i<18:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is " + str(response))
                if re.search("tcp:"+main.params['CTRL']['ip4'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE
            elif i>=18 and i<28:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is " + str(response))
                if re.search("tcp:"+main.params['CTRL']['ip5'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE
            else:
                response = main.Mininet1.get_sw_controller("s"+str(i))
                print("Response is" + str(response))
                if re.search("tcp:" +main.params['CTRL']['ip1'],response):
                    result = result and main.TRUE
                else:
                    result = main.FALSE

        utilities.assert_equals(expect = main.TRUE,actual=result,onpass="MasterControllers assigned correctly")
        for i in range (1,29):
            main.Mininet1.assign_sw_controller(sw=str(i),count=5,ip1=main.params['CTRL']['ip1'],port1=main.params['CTRL']['port1'],ip2=main.params['CTRL']['ip2'],port2=main.params['CTRL']['port2'],ip3=main.params['CTRL']['ip3'],port3=main.params['CTRL']['port3'],ip4=main.params['CTRL']['ip4'],port4=main.params['CTRL']['port4'],ip5=main.params['CTRL']['ip5'],port5=main.params['CTRL']['port5']) 

    def CASE3(self,main) :
        import time
        import json
        import re
        main.case("Adding Intents")
        intentIP = main.params['CTRL']['ip1']
        intentPort=main.params['INTENTS']['intentPort']
        intentURL=main.params['INTENTS']['intentURL']
        count = 1
        for i in range(8,18):
            srcMac = '00:00:00:00:00:' + str(hex(i)[2:]).zfill(2)
            dstMac = '00:00:00:00:00:'+str(hex(i+10)[2:])
            srcDPID = '00:00:00:00:00:00:30:'+str(i).zfill(2)
            dstDPID= '00:00:00:00:00:00:60:' +str(i+10)
            main.ONOS1.add_intent(intent_id=str(count),src_dpid=srcDPID,dst_dpid=dstDPID,src_mac=srcMac,dst_mac=dstMac,intentIP=intentIP,intentPort=intentPort,intentURL=intentURL)
            count+=1
            dstDPID = '00:00:00:00:00:00:30:'+str(i).zfill(2)
            srcDPID= '00:00:00:00:00:00:60:' +str(i+10)
            dstMac = '00:00:00:00:00:' + str(hex(i)[2:]).zfill(2)
            srcMac = '00:00:00:00:00:'+str(hex(i+10)[2:])
            main.ONOS1.add_intent(intent_id=str(count),src_dpid=srcDPID,dst_dpid=dstDPID,src_mac=srcMac,dst_mac=dstMac,intentIP=intentIP,intentPort=intentPort,intentURL=intentURL)
            count+=1
        count = 1
        i = 8
        result = main.TRUE
        while i <18 :
            main.log.info("\n\nh"+str(i)+" is Pinging h" + str(i+10))
            ping = main.Mininet1.pingHost(src="h"+str(i),target="h"+str(i+10))
            if ping ==main.FALSE and count <9:
                count+=1
                i = 8
                result = main.FALSE
                main.log.info("Ping FAILED! Making attempt number "+str(count) + "in 2 seconds")
                time.sleep(2)
            elif ping==main.FALSE:
                main.log.info("PINGS FAILED! MAX RETRIES REACHED!")
                i=19
                result = main.FALSE
            elif ping==main.TRUE:
                main.log.info("Ping passed!")
                i+=1
                result = main.TRUE
            else:
                main.log.info("ERROR!!")
                result = main.ERROR
        if result==main.FALSE:
            main.log.info("INTENTS HAVE NOT BEEN INSTALLED CORRECTLY!! EXITING!!!")
            main.cleanup()
            main.exit()
        

    def CASE4(self,main) :
        import time
        from subprocess import Popen, PIPE
        main.case("Setting up and Gathering data for current state")
        main.step("Get the current In-Memory Topology on each ONOS Instance")

        '''
        ctrls = []
        count = 1
        while True:
            temp = ()
            if ('ip'+str(count)) in main.params['CTRL']:
                temp = temp+(getattr(main,('ONOS'+str(count))),)
                temp = temp + ("ONOS"+str(count),)
                temp = temp + (main.params['CTRL']['ip'+str(count)],)
                temp = temp + (eval(main.params['CTRL']['port'+str(count)]),)
                ctrls.append(temp)
                count+=1
            else:
                break
        topo_result = main.TRUE

        for n in range(1,count):
            temp_result = main.Mininet1.compare_topo(ctrls,main.ONOS1.get_json(main.params['CTRL']['ip'+str(n)]+":"+main.params['CTRL']['restPort'+str(n)]+main.params['TopoRest']))
        '''

        main.step("Get the Mastership of each switch")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['switchURL']],stdout=PIPE).communicate()
        global masterSwitchList1
        masterSwitchList1 = stdout

        main.step("Get the High Level Intents")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['intentHighURL']],stdout=PIPE).communicate()
        global highIntentList1
        highIntentList1 = stdout
        
        main.step("Get the Low level Intents")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['intentLowURL']],stdout=PIPE).communicate()
        global lowIntentList1
        lowIntentList1= stdout
        
        main.step("Get the OF Table entries")
        global flows
        flows=[]
        for i in range(1,29):
            flows.append(main.Mininet2.get_flowTable("s"+str(i)))

        
        main.step("Start continuous pings")
        main.Mininet2.pingLong(src=main.params['PING']['source1'],target=main.params['PING']['target1'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source2'],target=main.params['PING']['target2'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source3'],target=main.params['PING']['target3'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source4'],target=main.params['PING']['target4'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source5'],target=main.params['PING']['target5'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source6'],target=main.params['PING']['target6'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source7'],target=main.params['PING']['target7'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source8'],target=main.params['PING']['target8'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source9'],target=main.params['PING']['target9'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source10'],target=main.params['PING']['target10'],pingTime=500)

        main.step("Create TestONTopology object")
        ctrls = []
        count = 1
        while True:
            temp = ()
            if ('ip' + str(count)) in main.params['CTRL']:
                temp = temp + (getattr(main,('ONOS' + str(count))),)
                temp = temp + ("ONOS"+str(count),)
                temp = temp + (main.params['CTRL']['ip'+str(count)],)
                temp = temp + (eval(main.params['CTRL']['port'+str(count)]),)
                ctrls.append(temp)
                count = count + 1
            else:
                break
        from sts.topology.teston_topology import TestONTopology # assumes that sts is already in you PYTHONPATH
        global MNTopo 
        Topo = TestONTopology(main.Mininet1, ctrls) # can also add Intent API info for intent operations
        MNTopo = Topo


    def CASE5(self,main) :
        import re
        main.case("MAIN COMPONENT FAILURE AND SCENARIO SPECIFIC TESTS")
        main.step("Zookeeper Server Failure!")
        result = main.TRUE
        master1 = main.ZK1.status()
        print master1
        if re.search("leader",master1):
            main.ZK1.kill()
            main.log.info("ZK1 was Master and Killed! Also Killing ZK2")
            main.ZK2.kill()
            time.sleep(10)
            if re.search("leader",main.ZK3.status()) or re.search("leader",main.ZK4.status()) or re.search("leader",main.ZK5.status()):
                result = main.TRUE
                main.log.info("New Leader Elected")
            else:
                result = main.FALSE
                main.log.info("NO NEW ZK LEADER ELECTED!!!")
        else:
            master2 = main.ZK2.status()
            if re.search("leader",master2):
                main.ZK2.kill()
                main.log.info("ZK2 was Master and Killed! Also Killing ZK3")
                main.ZK3.kill()
                time.sleep(10)
                if re.search("leader",main.ZK1.status()) or re.search("leader",main.ZK4.status()) or re.search("leader",main.ZK5.status()):
                    result = main.TRUE
                    main.log.info("New Leader Elected")
                else:
                    result = main.FALSE
                    main.log.info("NO NEW ZK LEADER ELECTED!!!")
            else:
                master3 = main.ZK3.status()
                if re.search("leader",master3):
                    main.ZK3.kill()
                    main.log.info("ZK3 was Master and Killed! Also Killing ZK4")
                    main.ZK4.kill()
                    time.sleep(10)
                    if re.search("leader",main.ZK1.status()) or re.search("leader",main.ZK2.status()) or re.search("leader",main.ZK5.status()):
                        result = main.TRUE
                        main.log.info("New Leader Elected")
                    else:
                        result = main.FALSE
                        main.log.info("NO NEW ZK LEADER ELECTED!!!")
                else:
                    master4 = main.ZK4.status()
                    if re.search("leader",master4):
                        main.ZK4.kill()
                        main.log.info("ZK4 was Master and Killed! Also Killing ZK5")
                        main.ZK5.kill()
                        time.sleep(10)
                        if re.search("leader",main.ZK1.status()) or re.search("leader",main.ZK2.status()) or re.search("leader",main.ZK3.status()):
                            result = main.TRUE
                            main.log.info("New Leader Elected")
                        else:
                            result = main.FALSE
                            main.log.info("NO NEW ZK LEADER ELECTED!!!")
                    else:
                        main.ZK5.kill()
                        main.log.info("ZK5 was Master and Killed! Also Killing ZK1")
                        main.ZK1.kill()
                        time.sleep(10)
                        if re.search("leader",main.ZK3.status()) or re.search("leader",main.ZK4.status()) or re.search("leader",main.ZK2.status()):
                            result = main.TRUE
                            main.log.info("New Leader Elected")
                        else:
                            result = main.FALSE
                            main.log.info("NO NEW ZK LEADER ELECTED!!!")
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="New Leader was Elected!",onfail="NO NEW LEADER WAS ELECTED!!!!")



    def CASE6(self,main) :
        import os
        main.case("Running ONOS Constant State Tests")
        main.step("Get the current In-Memory Topology on each ONOS Instance and Compare it to the Topology before component failure")

        main.step("Get the Mastership of each switch and compare to the Mastership before component failure")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['switchURL']],stdout=PIPE).communicate()
        result = main.TRUE
        for i in range(1,29):
            switchDPID = str(main.Mininet1.getSwitchDPID(switch="s"+str(i)))
            switchDPID = switchDPID[:2]+":"+switchDPID[2:4]+":"+switchDPID[4:6]+":"+switchDPID[6:8]+":"+switchDPID[8:10]+":"+switchDPID[10:12]+":"+switchDPID[12:14]+":"+switchDPID[14:]
            master1 = main.ZK1.findMaster(switchDPID=switchDPID,switchList=masterSwitchList1)
            master2 = main.ZK1.findMaster(switchDPID=switchDPID,switchList=stdout)
            if main.ZK1.findMaster(switchDPID=switchDPID,switchList=masterSwitchList1)==main.ZK1.findMaster(switchDPID=switchDPID,switchList=stdout):
                result = result and main.TRUE
            else:
                result = main.FALSE
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Mastership of Switches was not changed",onfail="MASTERSHIP OF SWITCHES HAS CHANGED!!!")
        result1 = result

        main.step("Get the High Level Intents and compare to before component failure")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['intentHighURL']],stdout=PIPE).communicate()
        changesInIntents=main.ONOS1.comp_intents(preIntents=highIntentList1,postIntents=stdout)
        if not changesInIntents:
            result = main.TRUE
        else:
            main.log.info("THERE WERE CHANGES TO THE HIGH LEVEL INTENTS! CHANGES WERE: "+str(changesInIntents))
            result = main.FALSE
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="No changes to High level Intents",onfail="CHANGES WERE MADE TO HIGH LEVEL INTENTS")
        result2=result

        main.step("Get the Low level Intents and compare to before component failure")
        (stdout,stderr)=Popen(["curl",main.params['CTRL']['ip1']+":"+main.params['CTRL']['restPort1']+main.params['CTRL']['intentLowURL']],stdout=PIPE).communicate()
        changesInIntents=main.ONOS1.comp_low(preIntents=lowIntentList1,postIntents=stdout)
        if not changesInIntents:
            result = main.TRUE
        else:
            main.log.info("THERE WERE CHANGES TO THE LOW LEVEL INTENTS! CHANGES WERE: "+str(changesInIntents))
            result = main.FALSE
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="No changes to Low level Intents",onfail="CHANGES WERE MADE TO LOW LEVEL INTENTS")
        result3=result


        main.step("Get the OF Table entries and compare to before component failure")
        result = main.TRUE
        flows2=[]
        for i in range(27):
            flows2.append(main.Mininet2.get_flowTable(sw="s"+str(i+1)))
            result = result and main.Mininet2.flow_comp(flow1=flows[i], flow2=main.Mininet2.get_flowTable(sw="s"+str(i+1)))
            if result == main.FALSE:
                main.log.info("DIFFERENCES IN FLOW TABLES FOR SWITCH "+str(i))
                break
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="No changes in the flow tables",onfail="CHANGES IN THE FLOW TABLES!!")
        result4 = result
        
        main.step("Check the continuous pings to ensure that no packets were dropped during component failure")
        main.Mininet2.pingKill()
        result = main.FALSE
        for i in range(8,18):
            result = result or main.Mininet2.checkForLoss("/tmp/ping.h"+str(i))
        if result==main.TRUE:
            main.log.info("LOSS IN THE PINGS!")
        elif result == main.ERROR:
            main.log.info("There are multiple mininet process running!!")
        else:
            main.log.info("No Loss in the pings!")
        utilities.assert_equals(expect=main.FALSE,actual=result,onpass="No Loss of connectivity!",onfail="LOSS OF CONNECTIVITY")
        result5=not result

        main.step("Check that ONOS Topology is consistent with MN Topology")
        ctrls = []
        count = 1
        while True:
            temp = ()
            if ('ip' + str(count)) in main.params['CTRL']:
                temp = temp + (getattr(main,('ONOS' + str(count))),)
                temp = temp + ("ONOS"+str(count),)
                temp = temp + (main.params['CTRL']['ip'+str(count)],)
                temp = temp + (eval(main.params['CTRL']['port'+str(count)]),)
                ctrls.append(temp)
                count = count + 1
            else:
                break


        result6 = main.TRUE
        for n in range(1,5):
            result = main.Mininet1.compare_topo(MNTopo, main.ONOS1.get_json(main.params['CTRL']['ip'+str(n)]+":"+main.params['CTRL']['restPort'+str(n)]+main.params['TopoRest']))
            utilities.assert_equals(expect=main.TRUE,actual=result,onpass="ONOS" + str(n) + " Topology matches MN Topology",onfail="ONOS" + str(n) + " Topology does not match MN Topology")
            result6 = result6 and result
        result = result1 and result2 and result3 and result4 and result5 and result6
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Constant State Tests Passed!",onfail="CONSTANT STATE TESTS FAILED!!")

    def CASE7 (self,main):
        main.case("Killing a link to Ensure that Link Discovery is Working Properly")
        main.step("Start continuous pings")
        main.Mininet2.pingLong(src=main.params['PING']['source1'],target=main.params['PING']['target1'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source2'],target=main.params['PING']['target2'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source3'],target=main.params['PING']['target3'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source4'],target=main.params['PING']['target4'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source5'],target=main.params['PING']['target5'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source6'],target=main.params['PING']['target6'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source7'],target=main.params['PING']['target7'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source8'],target=main.params['PING']['target8'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source9'],target=main.params['PING']['target9'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source10'],target=main.params['PING']['target10'],pingTime=500)

        main.step("Determine the current number of switches and links")
        (number,active)=main.ONOS1.num_switch(RestIP=main.params['CTRL']['ip1'])
        links = main.ONOS1.num_link(RestIP=main.params['CTRL']['ip1'])
        main.log.info("Currently there are %s switches, %s are active, and %s links" %(number,active,links))
        
        main.step("Kill Link between s3 and s28")
        main.Mininet1.link(END1="s3",END2="s28",OPTION="down")
        result = main.ONOS1.check_status_report(main.params['CTRL']['ip1'],active,str(int(links)-2))
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Link Down discovered properly",onfail="LINKS NOT DISCOVERED PROPERLY")
        result1 = result
        result = main.Mininet1.link(END1="s3",END2="s28",OPTION="up")

        main.step("Check for loss in pings when Link is brought down")
        main.Mininet2.pingKill()
        result = main.FALSE
        for i in range(8,18):
            result = result or main.Mininet2.checkForLoss("/tmp/ping.h"+str(i))
        if result==main.TRUE:
            main.log.info("LOSS IN THE PINGS!")
        elif result == main.ERROR:
            main.log.info("There are multiple mininet process running!!")
        else:
            main.log.info("No Loss in the pings!")
        utilities.assert_equals(expect=main.FALSE,actual=result,onpass="No Loss of connectivity!",onfail="LOSS OF CONNECTIVITY")
        result2 = result
        result = result1 and not result2
        utilities.assert_equals(expect=main.FALSE,actual=result,onpass="Link failure is discovered correctly and no traffic is lost!",onfail="Link Discovery failed or traffic was dropped!!!")
        

    
    def CASE8 (self, main) :
        import time
        main.case("Killing a switch to ensure switch discovery is working properly")
        main.step("Start continuous pings")
        main.Mininet2.pingLong(src=main.params['PING']['source1'],target=main.params['PING']['target1'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source2'],target=main.params['PING']['target2'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source3'],target=main.params['PING']['target3'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source4'],target=main.params['PING']['target4'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source5'],target=main.params['PING']['target5'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source6'],target=main.params['PING']['target6'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source7'],target=main.params['PING']['target7'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source8'],target=main.params['PING']['target8'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source9'],target=main.params['PING']['target9'],pingTime=500)
        main.Mininet2.pingLong(src=main.params['PING']['source10'],target=main.params['PING']['target10'],pingTime=500)

        main.step("Determine the current number of switches and links")
        (number,active)=main.ONOS1.num_switch(RestIP=main.params['CTRL']['ip1'])
        links = main.ONOS1.num_link(RestIP=main.params['CTRL']['ip1'])
        main.log.info("Currently there are %s switches, %s are active, and %s links" %(number,active,links))
        
        main.step("Kill s28 ")
        main.Mininet2.del_switch("s28")
        time.sleep(31)
        result = main.ONOS1.check_status_report(main.params['CTRL']['ip1'],str(int(active)-1),str(int(links)-4))
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Switch Discovery is Working",onfail="Switch Discovery FAILED TO WORK PROPERLY!")

        main.step("Add back s28")
        main.Mininet2.add_switch("s28")
        main.Mininet1.assign_sw_controller(sw="28",ip1=main.params['CTRL']['ip1'],port1=main.params['CTRL']['port1'])
        main.Mininet1.assign_sw_controller(sw="28",count=5,ip1=main.params['CTRL']['ip1'],port1=main.params['CTRL']['port1'],ip2=main.params['CTRL']['ip2'],port2=main.params['CTRL']['port2'],ip3=main.params['CTRL']['ip3'],port3=main.params['CTRL']['port3'],ip4=main.params['CTRL']['ip4'],port4=main.params['CTRL']['port4'],ip5=main.params['CTRL']['ip5'],port5=main.params['CTRL']['port5']) 
        time.sleep(31)
        result = main.ONOS1.check_status_report(main.params['CTRL']['ip1'],active,links)
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Switch Discovery is Working",onfail="Switch Discovery FAILED TO WORK PROPERLY!")
        result1=result

        main.step("Checking for Traffic Loss")
        main.Mininet2.pingKill()
        result = main.FALSE
        for i in range(8,18):
            result = result or main.Mininet2.checkForLoss("/tmp/ping.h"+str(i))
        if result==main.TRUE:
            main.log.info("LOSS IN THE PINGS!")
        elif result == main.ERROR:
            main.log.info("There are multiple mininet process running!!")
        else:
            main.log.info("No Loss in the pings!")
        utilities.assert_equals(expect=main.FALSE,actual=result,onpass="No Loss of connectivity!",onfail="LOSS OF CONNECTIVITY")
        result = not result and result1
        utilities.assert_equals(expect=main.TRUE,actual=result,onpass="Switch Discovered Correctly and No Loss of traffic",onfail="Switch discovery failed or there was loss of traffic")

# Authored by James Lee
# Just wanted to see how many people were paying attention here.
# Elayne Boosler once said "I have six locks on my door all in a row
# When I go out, I lock every other one. I figure no matter how long 
# somebody stands there picking the locks, they are always locking three"