TestON/tests/TopoConvNext/TopoConvNext.py

#TopoPerfNext
#
#Topology Convergence scale-out test for ONOS-next
#NOTE: This test supports up to 7 nodes scale-out scenario
#
#andrew@onlab.us

import time
import sys
import os
import re

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

    def CASE1(self, main):
        '''
        ONOS startup sequence
        '''
        import time

        #******
        #Global cluster count for scale-out purposes
        global cluster_count 
        cluster_count = 1 
        #******
        cell_name = main.params['ENV']['cellName']

        git_pull = main.params['GIT']['autoPull']
        checkout_branch = main.params['GIT']['checkout']

        ONOS1_ip = main.params['CTRL']['ip1']
        ONOS2_ip = main.params['CTRL']['ip2']
        ONOS3_ip = main.params['CTRL']['ip3']
        ONOS4_ip = main.params['CTRL']['ip4']
        ONOS5_ip = main.params['CTRL']['ip5']
        ONOS6_ip = main.params['CTRL']['ip6']
        ONOS7_ip = main.params['CTRL']['ip7']
        MN1_ip = main.params['MN']['ip1']
        BENCH_ip = main.params['BENCH']['ip']

        main.case("Setting up test environment")
        main.log.report("Setting up test environment")

        main.step("Creating cell file")
        cell_file_result = main.ONOSbench.create_cell_file(
                BENCH_ip, cell_name, MN1_ip, "onos-core",
                ONOS1_ip, ONOS2_ip, ONOS3_ip, ONOS4_ip,
                ONOS5_ip, ONOS6_ip, ONOS7_ip)

        main.step("Applying cell file to environment")
        cell_apply_result = main.ONOSbench.set_cell(cell_name)
        verify_cell_result = main.ONOSbench.verify_cell()
        
        main.step("Git checkout and pull "+checkout_branch)
        if git_pull == 'on':
            checkout_result = \
                    main.ONOSbench.git_checkout(checkout_branch)
            pull_result = main.ONOSbench.git_pull()
        else:
            checkout_result = main.TRUE
            pull_result = main.TRUE
            main.log.info("Skipped git checkout and pull")

        main.step("Using mvn clean & install")
        #mvn_result = main.ONOSbench.clean_install()
        mvn_result = main.TRUE

        main.step("Set cell for ONOS cli env")
        main.ONOS1cli.set_cell(cell_name)
        main.ONOS2cli.set_cell(cell_name)
        main.ONOS3cli.set_cell(cell_name)
        main.ONOS4cli.set_cell(cell_name)
        main.ONOS5cli.set_cell(cell_name)
        main.ONOS6cli.set_cell(cell_name)
        main.ONOS7cli.set_cell(cell_name)
    
        main.step("Creating ONOS package")
        package_result = main.ONOSbench.onos_package()

        #Start test with single node only
        main.step("Installing ONOS package")
        install1_result = main.ONOSbench.onos_install(node=ONOS1_ip)

        time.sleep(10)

        main.step("Start onos cli")
        cli1 = main.ONOS1cli.start_onos_cli(ONOS1_ip)

        main.step("Enable metrics feature")
        main.ONOS1cli.feature_install("onos-app-metrics")

        utilities.assert_equals(expect=main.TRUE,
                actual= cell_file_result and cell_apply_result and\
                        verify_cell_result and checkout_result and\
                        pull_result and mvn_result and\
                        install1_result,
                onpass="Test Environment setup successful",
                onfail="Failed to setup test environment")
    
    def CASE2(self, main):
        '''
        100 Switch discovery latency

        Important:
            This test case can be potentially dangerous if 
            your machine has previously set iptables rules.
            One of the steps of the test case will flush
            all existing iptables rules.
        Note:
            You can specify the number of switches in the 
            params file to adjust the switch discovery size
            (and specify the corresponding topology in Mininet1 
            .topo file)
        '''
        import time
        import subprocess
        import os
        import requests
        import json
        import numpy

        ONOS_ip_list = []
        ONOS_ip_list.append('0')
        ONOS_ip_list.append(main.params['CTRL']['ip1'])
        ONOS_ip_list.append(main.params['CTRL']['ip2'])
        ONOS_ip_list.append(main.params['CTRL']['ip3'])
        ONOS_ip_list.append(main.params['CTRL']['ip4'])
        ONOS_ip_list.append(main.params['CTRL']['ip5'])
        ONOS_ip_list.append(main.params['CTRL']['ip6'])
        ONOS_ip_list.append(main.params['CTRL']['ip7'])
        MN1_ip = main.params['MN']['ip1']
        ONOS_user = main.params['CTRL']['user']

        default_sw_port = main.params['CTRL']['port1']
       
        #Number of iterations of case
        num_iter = main.params['TEST']['numIter']
        num_sw = main.params['TEST']['numSwitch']

        #Timestamp 'keys' for json metrics output.
        #These are subject to change, hence moved into params
        deviceTimestamp = main.params['JSON']['deviceTimestamp']
        graphTimestamp = main.params['JSON']['graphTimestamp']
        
        #Threshold for this test case
        sw_disc_threshold_str = main.params['TEST']['swDisc100Threshold']
        sw_disc_threshold_obj = sw_disc_threshold_str.split(",")
        sw_disc_threshold_min = int(sw_disc_threshold_obj[0])
        sw_disc_threshold_max = int(sw_disc_threshold_obj[1])

        assertion = main.TRUE
        sw_discovery_lat_list = []

        main.case(str(num_sw)+" switch per "+str(cluster_count)+
                " nodes convergence latency")
       
        main.log.report("Currently active ONOS node(s): ")
        report_str = "Node "
        for node in range(1, cluster_count+1):
            report_str += (str(node) + " ") 
        main.log.report(report_str)
        
        main.step("Assigning "+num_sw+" switches to each ONOS")
        index = 1 
        for node in range(1, cluster_count+1):
            for i in range(index, int(num_sw)+index):
                main.Mininet1.assign_sw_controller(
                        sw=str(i),
                        ip1=ONOS_ip_list[node],
                        port1=default_sw_port)
            index = i+1 

        main.log.info("Please check ptpd configuration to ensure "+\
                "all nodes' system times are in sync")

        time.sleep(10)

        for i in range(0, int(num_iter)):
            main.step("Set iptables rule to block sw connections")
               
            #INPUT rules
            main.ONOS1.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS2.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS3.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS4.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS5.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS6.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS7.handle.sendline(
                    "sudo iptables -A INPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
               
                #OUTPUT rules
            main.ONOS1.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS2.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS3.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS4.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS5.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS6.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")
            main.ONOS7.handle.sendline(
                    "sudo iptables -A OUTPUT -p tcp -s "+
                    MN1_ip+" --dport "+default_sw_port+" -j DROP")

            main.log.info("Please wait for switch connection to timeout")
            time.sleep(60)

            main.step("Flushing iptables and obtaining t0")
            t0_system = time.time()*1000
            main.ONOS1.handle.sendline("sudo iptables -F")
            main.ONOS2.handle.sendline("sudo iptables -F")
            main.ONOS3.handle.sendline("sudo iptables -F")
            main.ONOS4.handle.sendline("sudo iptables -F")
            main.ONOS5.handle.sendline("sudo iptables -F")
            main.ONOS6.handle.sendline("sudo iptables -F")
            main.ONOS7.handle.sendline("sudo iptables -F")

            counter_loop = 0
            counter_avail1 = 0
            counter_avail2 = 0
            counter_avail3 = 0
            counter_avail4 = 0
            counter_avail5 = 0
            counter_avail6 = 0
            counter_avail7 = 0
            onos1_dev = False
            onos2_dev = False
            onos3_dev = False
            onos4_dev = False
            onos5_dev = False
            onos6_dev = False
            onos7_dev = False

            #TODO: Think of a more elegant way to check all 
            #      switches across all nodes
            #Goodluck debugging this loop
            while counter_loop < 60:
                for node in range(1, cluster_count+1):
                    if node == 1 and not onos1_dev:
                        device_str_obj1 = main.ONOS1cli.devices()
                        print device_str_obj1
                        device_json1 = json.loads(device_str_obj1)
                        for device1 in device_json1:
                            if device1['available'] == True:
                                counter_avail1 += 1
                                if counter_avail1 == int(num_sw):
                                    onos1_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS1")
                                else:
                                    counter_avail1 = 0
                    if node == 2 and not onos2_dev:
                        device_str_obj2 = main.ONOS2cli.devices()
                        device_json2 = json.loads(device_str_obj2)
                        for device2 in device_json2:
                            if device2['available'] == True:
                                counter_avail2 += 1
                                if counter_avail2 == int(num_sw):
                                    onos2_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS2")
                                else:
                                    counter_avail2 = 0
                    if node == 3 and not onos3_dev:
                        device_str_obj3 = main.ONOS3cli.devices()
                        device_json3 = json.loads(device_str_obj3)
                        for device3 in device_json3:
                            if device3['available'] == True:
                                counter_avail3 += 1
                                if counter_avail3 == int(num_sw):
                                    onos3_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS3")
                                else:
                                    counter_avail3 = 0
                    if node == 4 and not onos4_dev:
                        device_str_obj4 = main.ONOS4cli.devices()
                        device_json4 = json.loads(device_str_obj4)
                        for device4 in device_json4:
                            if device4['available'] == True:
                                counter_avail4 += 1
                                if counter_avail4 == int(num_sw):
                                    onos4_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS4")
                                else:
                                    counter_avail4 = 0
                    if node == 5 and not onos5_dev:
                        device_str_obj5 = main.ONOS5cli.devices()
                        device_json5 = json.loads(device_str_obj5)
                        for device5 in device_json5:
                            if device5['available'] == True:
                                counter_avail5 += 1
                                if counter_avail5 == int(num_sw):
                                    onos5_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS5")
                                else:
                                    counter_avail5 = 0
                    if node == 6 and not onos6_dev:
                        device_str_obj6 = main.ONOS6cli.devices()
                        device_json6 = json.loads(device_str_obj6)
                        for device6 in device_json6:
                            if device6['available'] == True:
                                counter_avail6 += 1
                                if counter_avail6 == int(num_sw):
                                    onos6_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS6")
                                else:
                                    counter_avail6 = 0
                    if node == 7 and not onos7_dev:
                        device_str_obj7 = main.ONOS7cli.devices()
                        device_json7 = json.loads(device_str_obj7)
                        for device7 in device_json7:
                            if device7['available'] == True:
                                counter_avail7 += 1
                                if counter_avail7 == int(num_sw):
                                    onos7_dev = True
                                    main.log.info("All devices have been"+
                                            " discovered on ONOS7")
                                else:
                                    counter_avail7 = 0
                    #END node loop
              
                #TODO: clean up this mess of an if statements if possible
                #Treat each if as a separate test case with the given
                #     cluster count. Hence when the cluster count changes
                #     the desired calculations will be made
                if cluster_count == 1:
                    if onos1_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        
                        if graph_lat_1 > sw_disc_threshold_min\
                            and graph_lat_1 < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    graph_lat_1)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")

                        #Break while loop 
                        break
                if cluster_count == 2:
                    if onos1_dev and onos2_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2)) / 2

                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")

                        break
                if cluster_count == 3:
                    if onos1_dev and onos2_dev and onos3_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_str_metrics_3 =\
                            main.ONOS3cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        json_obj_3 = json.loads(json_str_metrics_3)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        graph_timestamp_3 =\
                            json_obj_3[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)
                        graph_lat_3 = \
                            int(graph_timestamp_3) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2) +\
                             int(graph_lat_3)) / 3 
                        
                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")
                        
                        break
                if cluster_count == 4:
                    if onos1_dev and onos2_dev and onos3_dev and\
                       onos4_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_str_metrics_3 =\
                            main.ONOS3cli.topology_events_metrics()
                        json_str_metrics_4 =\
                            main.ONOS4cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        json_obj_3 = json.loads(json_str_metrics_3)
                        json_obj_4 = json.loads(json_str_metrics_4)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        graph_timestamp_3 =\
                            json_obj_3[graphTimestamp]['value']
                        graph_timestamp_4 =\
                            json_obj_4[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)
                        graph_lat_3 = \
                            int(graph_timestamp_3) - int(t0_system)
                        graph_lat_4 = \
                            int(graph_timestamp_4) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2) +\
                             int(graph_lat_3) +\
                             int(graph_lat_4)) / 4 
                        
                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")
                
                        break
                if cluster_count == 5:
                    if onos1_dev and onos2_dev and onos3_dev and\
                       onos4_dev and onos5_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_str_metrics_3 =\
                            main.ONOS3cli.topology_events_metrics()
                        json_str_metrics_4 =\
                            main.ONOS4cli.topology_events_metrics()
                        json_str_metrics_5 =\
                            main.ONOS5cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        json_obj_3 = json.loads(json_str_metrics_3)
                        json_obj_4 = json.loads(json_str_metrics_4)
                        json_obj_5 = json.loads(json_str_metrics_5)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        graph_timestamp_3 =\
                            json_obj_3[graphTimestamp]['value']
                        graph_timestamp_4 =\
                            json_obj_4[graphTimestamp]['value']
                        graph_timestamp_5 =\
                            json_obj_5[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)
                        graph_lat_3 = \
                            int(graph_timestamp_3) - int(t0_system)
                        graph_lat_4 = \
                            int(graph_timestamp_4) - int(t0_system)
                        graph_lat_5 = \
                            int(graph_timestamp_5) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2) +\
                             int(graph_lat_3) +\
                             int(graph_lat_4) +\
                             int(graph_lat_5)) / 5 
                        
                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")
                
                        break
                if cluster_count == 6:
                    if onos1_dev and onos2_dev and onos3_dev and\
                       onos4_dev and onos5_dev and onos6_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_str_metrics_3 =\
                            main.ONOS3cli.topology_events_metrics()
                        json_str_metrics_4 =\
                            main.ONOS4cli.topology_events_metrics()
                        json_str_metrics_5 =\
                            main.ONOS5cli.topology_events_metrics()
                        json_str_metrics_6 =\
                            main.ONOS6cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        json_obj_3 = json.loads(json_str_metrics_3)
                        json_obj_4 = json.loads(json_str_metrics_4)
                        json_obj_5 = json.loads(json_str_metrics_5)
                        json_obj_6 = json.loads(json_str_metrics_6)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        graph_timestamp_3 =\
                            json_obj_3[graphTimestamp]['value']
                        graph_timestamp_4 =\
                            json_obj_4[graphTimestamp]['value']
                        graph_timestamp_5 =\
                            json_obj_5[graphTimestamp]['value']
                        graph_timestamp_6 =\
                            json_obj_6[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)
                        graph_lat_3 = \
                            int(graph_timestamp_3) - int(t0_system)
                        graph_lat_4 = \
                            int(graph_timestamp_4) - int(t0_system)
                        graph_lat_5 = \
                            int(graph_timestamp_5) - int(t0_system)
                        graph_lat_6 = \
                            int(graph_timestamp_6) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2) +\
                             int(graph_lat_3) +\
                             int(graph_lat_4) +\
                             int(graph_lat_5) +\
                             int(graph_lat_6)) / 6 
                        
                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")
                        
                        break
                if cluster_count == 7:
                    if onos1_dev and onos2_dev and onos3_dev and\
                       onos4_dev and onos5_dev and onos6_dev and\
                       onos7_dev:
                        main.log.info("All devices have been discovered"+
                            " on all ONOS instances")
                        json_str_metrics_1 =\
                            main.ONOS1cli.topology_events_metrics()
                        json_str_metrics_2 =\
                            main.ONOS2cli.topology_events_metrics()
                        json_str_metrics_3 =\
                            main.ONOS3cli.topology_events_metrics()
                        json_str_metrics_4 =\
                            main.ONOS4cli.topology_events_metrics()
                        json_str_metrics_5 =\
                            main.ONOS5cli.topology_events_metrics()
                        json_str_metrics_6 =\
                            main.ONOS6cli.topology_events_metrics()
                        json_str_metrics_7 =\
                            main.ONOS7cli.topology_events_metrics()
                        json_obj_1 = json.loads(json_str_metrics_1)
                        json_obj_2 = json.loads(json_str_metrics_2)
                        json_obj_3 = json.loads(json_str_metrics_3)
                        json_obj_4 = json.loads(json_str_metrics_4)
                        json_obj_5 = json.loads(json_str_metrics_5)
                        json_obj_6 = json.loads(json_str_metrics_6)
                        json_obj_7 = json.loads(json_str_metrics_7)
                        graph_timestamp_1 =\
                            json_obj_1[graphTimestamp]['value']
                        graph_timestamp_2 =\
                            json_obj_2[graphTimestamp]['value']
                        graph_timestamp_3 =\
                            json_obj_3[graphTimestamp]['value']
                        graph_timestamp_4 =\
                            json_obj_4[graphTimestamp]['value']
                        graph_timestamp_5 =\
                            json_obj_5[graphTimestamp]['value']
                        graph_timestamp_6 =\
                            json_obj_6[graphTimestamp]['value']
                        graph_timestamp_7 =\
                            json_obj_7[graphTimestamp]['value']
                        
                        graph_lat_1 = \
                            int(graph_timestamp_1) - int(t0_system)
                        graph_lat_2 = \
                            int(graph_timestamp_2) - int(t0_system)
                        graph_lat_3 = \
                            int(graph_timestamp_3) - int(t0_system)
                        graph_lat_4 = \
                            int(graph_timestamp_4) - int(t0_system)
                        graph_lat_5 = \
                            int(graph_timestamp_5) - int(t0_system)
                        graph_lat_6 = \
                            int(graph_timestamp_6) - int(t0_system)
                        graph_lat_7 = \
                            int(graph_timestamp_7) - int(t0_system)

                        avg_graph_lat = \
                            (int(graph_lat_1) +\
                             int(graph_lat_2) +\
                             int(graph_lat_3) +\
                             int(graph_lat_4) +\
                             int(graph_lat_5) +\
                             int(graph_lat_6) +\
                             int(graph_lat_7)) / 7 
                        
                        if avg_graph_lat > sw_disc_threshold_min\
                            and avg_graph_lat < sw_disc_threshold_max:
                            sw_discovery_lat_list.append(
                                    avg_graph_lat)
                        else:
                            main.log.info("Switch discovery latency "+
                                "exceeded the threshold.")
                        
                        break
                
                counter_loop += 1
                time.sleep(3)
                #END WHILE LOOP            
            #END ITERATION LOOP
        #REPORT HERE 

        if len(sw_discovery_lat_list) > 0:
            sw_lat_avg = sum(sw_discovery_lat_list) / \
                     len(sw_discovery_lat_list)
            sw_lat_dev = numpy.dev(sw_discovery_lat_list)
        else: 
            assertion = main.FALSE

        main.log.report("Switch discovery lat for "+\
            str(cluster_count)+" instances, 100 sw each: ")
        main.log.report("Avg: "+str(sw_lat_avg)+" ms")
        main.log.report("Std Deviation: "+str(sw_lat_dev)+" ms")

        utilities.assert_equals(expect=main.TRUE, actual=assertion,
                onpass="Switch discovery convergence latency" +\
                        " test successful",
                onfail="Switch discovery convergence latency" +\
                        " test failed")
        

    def CASE3(self, main):
        '''
        Increase number of nodes and initiate CLI
        '''
        import time
        import subprocess
        import os
        import requests
        import json
       
        ONOS_ip_list = []
        ONOS_ip_list.append('0') #Append 0 for index 0
        ONOS_ip_list.append(main.params['CTRL']['ip1'])
        ONOS_ip_list.append(main.params['CTRL']['ip2'])
        ONOS_ip_list.append(main.params['CTRL']['ip3'])
        ONOS_ip_list.append(main.params['CTRL']['ip4'])
        ONOS_ip_list.append(main.params['CTRL']['ip5'])
        ONOS_ip_list.append(main.params['CTRL']['ip6'])
        ONOS_ip_list.append(main.params['CTRL']['ip7'])
        
        MN1_ip = main.params['MN']['ip1']
        BENCH_ip = main.params['BENCH']['ip']
 
        #NOTE:We start with cluster_count at 1. The first 
        #case already initialized ONOS1. Increase the
        #cluster count and start from 2.
        #You can optionally change the increment to
        #test steps of node sizes, such as 1,3,5,7
        
        global cluster_count
        cluster_count += 2 
       
        #Supports up to 7 node configuration
        for node in range(1, cluster_count+1):
            if node == 2:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS3cli.start_onos_cli(ONOS_ip_list[node])
            elif node == 3:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS3cli.start_onos_cli(ONOS_ip_list[node])
            elif node == 4:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS4cli.start_onos_cli(ONOS_ip_list[node])
            elif node == 5:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS5cli.start_onos_cli(ONOS_ip_list[node])
            elif node == 6:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS6cli.start_onos_cli(ONOS_ip_list[node])
            elif node == 7:
                main.log.info("Starting CLI for instance "+
                        ONOS_ip_list[node])
                main.ONOS7cli.start_onos_cli(ONOS_ip_list[node]) 
            time.sleep(5)