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Case Study: Mixing Healthcheck & Failover

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For this example, we use the same topology used in the Failover part. The idea here is to use VRRP VIPs as LVS VIPs. That way we will introduce a High Available LVS director performing LVS real server pool monitoring.

Keepalived Configuration

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The whole configuration is done in the /etc/keepalived/keepalived.conf file. In

our case study this file on LVS director 1 looks like::

    # Configuration File for keepalived

    global_defs {

        notification_email {

            admin@domain.com

            0633225522@domain.com

        }

        notification_email_from keepalived@domain.com

        smtp_server 192.168.200.20

        smtp_connect_timeout 30

        lvs_id LVS_MAIN

    }

    # VRRP Instances definitions

    vrrp_sync_group VG1 {

        group {

            VI_1

            VI_2

        }

    }

    vrrp_sync_group VG2 {

        group {

            VI_3

            VI_4

        }

    }

    vrrp_instance VI_1 {

        state MASTER

        interface eth0

        virtual_router_id 51

        priority 150

        advert_int 1

        authentication {

            auth_type PASS

            auth_pass k@l!ve1

        }

        virtual_ipaddress {

            192.168.200.10

            192.168.200.11

        }

    }

    vrrp_instance VI_2 {

        state MASTER

        interface eth1

        virtual_router_id 52

        priority 150

        advert_int 1

        authentication {

            auth_type PASS

            auth_pass k@l!ve2

        }

        virtual_ipaddress {

            192.168.100.10

        }

    }

    vrrp_instance VI_3 {

        state BACKUP

        interface eth0

        virtual_router_id 53

        priority 100

        advert_int 1

        authentication {

            auth_type PASS

            auth_pass k@l!ve3

        }

        virtual_ipaddress {

            192.168.200.12

            192.168.200.13

        }

    }

    vrrp_instance VI_4 {

        state BACKUP

        interface eth1

        virtual_router_id 54

        priority 100

        advert_int 1

        authentication {

            auth_type PASS

            auth_pass k@l!ve4

        }

        virtual_ipaddress {

            192.168.100.11

        }

    }

    # Virtual Servers definitions

    virtual_server 192.168.200.10 80 {

        delay_loop 30

        lb_algo wrr

        lb_kind NAT

        persistence_timeout 50

        protocol TCP

        sorry_server 192.168.100.100 80

        real_server 192.168.100.2 80 {

            weight 2

            HTTP_GET {

                url {

                    path /testurl/test.jsp

                    digest ec90a42b99ea9a2f5ecbe213ac9eba03

                }

                url {

                    path /testurl2/test.jsp

                    digest 640205b7b0fc66c1ea91c463fac6334c

                }

                connect_timeout 3

                retry 3

                delay_before_retry 2

            }

        }

        real_server 192.168.100.3 80 {

            weight 1

            HTTP_GET {

                url {

                    path /testurl/test.jsp

                    digest 640205b7b0fc66c1ea91c463fac6334c

                }

                connect_timeout 3

                retry 3

                delay_before_retry 2

            }

        }

    }

    virtual_server 192.168.200.12 443 {

        delay_loop 20

        lb_algo rr

        lb_kind NAT

        persistence_timeout 360

        protocol TCP

        real_server 192.168.100.2 443 {

            weight 1

            TCP_CHECK {

                connect_timeout 3

            }

        }

        real_server 192.168.100.3 443 {

            weight 1

            TCP_CHECK {

                connect_timeout 3

            }

        }

    }

We define the symmetric VRRP configuration file on LVS director 2. That way both directors are active at a time, director 1 handling HTTP stream and director 2 SSL stream.