Linux – Both servers running keepalived become master and have a same Virtual IP

keepalivedlinuxnetworkingnginx

Both two servers started keepalived, and the BACKUP server transited to MASTER STATE immediately.
both two became MASTER now.

Both two nodes are sending VRRP advertisement msg.

on master server:

[root@zhsq1 ~]# tcpdump -c 3 -i em1 host 224.0.0.18
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on em1, link-type EN10MB (Ethernet), capture size 65535 bytes
11:01:35.526355 IP zhsq1 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 153, authtype simple, intvl 1s, length 20
11:01:36.526497 IP zhsq1 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 153, authtype simple, intvl 1s, length 20
11:01:37.527561 IP zhsq1 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 153, authtype simple, intvl 1s, length 20

on the backup server:

[root@zhsq2 ~]# tcpdump -c 3 -i em1 host 224.0.0.18
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on em1, link-type EN10MB (Ethernet), capture size 65535 bytes
11:11:04.314996 IP zhsq2 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 102, authtype simple, intvl 1s, length 20
11:11:05.315111 IP zhsq2 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 102, authtype simple, intvl 1s, length 20
11:11:06.316175 IP zhsq2 > 224.0.0.18: VRRPv2, Advertisement, vrid 51, prio 102, authtype simple, intvl 1s, length 20

below is the master server log:

May 31 11:00:22 zhsq1 Keepalived[31475]: Starting Keepalived v1.2.7 (05/20,2013)
May 31 11:00:22 zhsq1 Keepalived[31476]: Starting Healthcheck child process, pid=31477
May 31 11:00:22 zhsq1 Keepalived[31476]: Starting VRRP child process, pid=31478
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Interface queue is empty
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: No such interface, em2
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Netlink reflector reports IP 10.0.7.60 added
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Netlink reflector reports IP fe80::92b1:1cff:fe4c:bea8 added
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Registering Kernel netlink reflector
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Registering Kernel netlink command channel
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Interface queue is empty
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: No such interface, em2
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Netlink reflector reports IP 10.0.7.60 added
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Netlink reflector reports IP fe80::92b1:1cff:fe4c:bea8 added
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Registering Kernel netlink reflector
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Registering Kernel netlink command channel
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Registering gratuitous ARP shared channel
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Opening file '/etc/keepalived/keepalived.conf'.
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Configuration is using : 4661 Bytes
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Opening file '/etc/keepalived/keepalived.conf'.
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Configuration is using : 63856 Bytes
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: Using LinkWatch kernel netlink reflector...
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: VRRP sockpool: [ifindex(2), proto(112), fd(11,12)]
May 31 11:00:22 zhsq1 Keepalived_healthcheckers[31477]: Using LinkWatch kernel netlink reflector...
May 31 11:00:22 zhsq1 Keepalived_vrrp[31478]: VRRP_Script(chk_http_port) succeeded
May 31 11:00:23 zhsq1 Keepalived_vrrp[31478]: VRRP_Instance(VI_1) Transition to MASTER STATE
May 31 11:00:24 zhsq1 Keepalived_vrrp[31478]: VRRP_Instance(VI_1) Entering MASTER STATE
May 31 11:00:24 zhsq1 Keepalived_vrrp[31478]: VRRP_Instance(VI_1) setting protocol VIPs.
May 31 11:00:24 zhsq1 Keepalived_vrrp[31478]: VRRP_Instance(VI_1) Sending gratuitous ARPs on em1 for 10.0.7.65
May 31 11:00:24 zhsq1 Keepalived_healthcheckers[31477]: Netlink reflector reports IP 10.0.7.65 added
May 31 11:00:29 zhsq1 Keepalived_vrrp[31478]: VRRP_Instance(VI_1) Sending gratuitous ARPs on em1 for 10.0.7.65

below is the backup server log:

May 31 11:01:50 zhsq2 Keepalived[31250]: Starting Keepalived v1.2.7 (05/20,2013)
May 31 11:01:50 zhsq2 Keepalived[31251]: Starting Healthcheck child process, pid=31252
May 31 11:01:50 zhsq2 Keepalived[31251]: Starting VRRP child process, pid=31253
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Interface queue is empty
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: No such interface, em2
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Netlink reflector reports IP 10.0.7.61 added
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Netlink reflector reports IP fe80::92b1:1cff:fe4c:b8b7 added
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Registering Kernel netlink reflector
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Registering Kernel netlink command channel
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Interface queue is empty
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: No such interface, em2
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Netlink reflector reports IP 10.0.7.61 added
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Netlink reflector reports IP fe80::92b1:1cff:fe4c:b8b7 added
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Registering Kernel netlink reflector
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Registering Kernel netlink command channel
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Registering gratuitous ARP shared channel
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Opening file '/etc/keepalived/keepalived.conf'.
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Configuration is using : 4661 Bytes
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Opening file '/etc/keepalived/keepalived.conf'.
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Configuration is using : 63856 Bytes
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: Using LinkWatch kernel netlink reflector...
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) Entering BACKUP STATE
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: VRRP sockpool: [ifindex(2), proto(112), fd(11,12)]
May 31 11:01:50 zhsq2 Keepalived_healthcheckers[31252]: Using LinkWatch kernel netlink reflector...
May 31 11:01:50 zhsq2 Keepalived_vrrp[31253]: VRRP_Script(chk_http_port) succeeded
May 31 11:01:54 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) Transition to MASTER STATE
May 31 11:01:55 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) Entering MASTER STATE
May 31 11:01:55 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) setting protocol VIPs.
May 31 11:01:55 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) Sending gratuitous ARPs on em1 for 10.0.7.65
May 31 11:01:55 zhsq2 Keepalived_healthcheckers[31252]: Netlink reflector reports IP 10.0.7.65 added
May 31 11:02:00 zhsq2 Keepalived_vrrp[31253]: VRRP_Instance(VI_1) Sending gratuitous ARPs on em1 for 10.0.7.65

the master server's keepalived conf is below:

vrrp_script chk_http_port {         
        script "/opt/nginx/nginx_pid.sh"
        interval 2 
        weight 2  
}

vrrp_instance VI_1 {  
        state MASTER
        #nopreempt 
        interface em1
        virtual_router_id 51 
        priority 151
        mcast_src_ip 10.0.7.60 
        track_interface {
                em1
        }
        authentication {  
                auth_type PASS 
                auth_pass 1111 
        }  
        track_script {  
                chk_http_port 
        }  
        virtual_ipaddress {                  
                10.0.7.65 dev em1
        }  
}

the backup server's keepalived conf is below:

vrrp_script chk_http_port {
        script "/opt/nginx/nginx_pid.sh"
        interval 2
        weight 2
}

vrrp_instance VI_1 {
        state BACKUP
        interface em1
        virtual_router_id 51
        priority 100
        mcast_src_ip 10.0.7.61
        track_interface {
                em1
        }
        authentication {
                auth_type PASS
                auth_pass 1111
        }
        track_script {
                chk_http_port
        }
        virtual_ipaddress {
                10.0.7.65 dev em1
        }
}

the chk_http_port file is below:

NGINX_PROCESS=`ps -C nginx --no-header | wc -l`

if [ $NGINX_PROCESS -eq 0 ]; then

        /usr/local/nginx/sbin/nginx

        sleep 3

        if [ `ps -C nginx --no-header | wc -l` -eq 0 ]; then

                killall keepalived 

        fi  

fi

Please help me.

Thanks a lot.

Best Answer

Packets are not passing between machines on the em1 interface (causing a split brain scenario as Mike states).

check your firewall to ensure packets aren't being caught
check your networking to ensure em1 is the same network on both machines

Here's an example of what one of the packets looks like:

Frame 2: 54 bytes on wire (432 bits), 54 bytes captured (432 bits)
    Arrival Time: Jun  1, 2013 03:39:50.709520000 UTC
    Epoch Time: 1370057990.709520000 seconds
    [Time delta from previous captured frame: 0.000970000 seconds]
    [Time delta from previous displayed frame: 0.000970000 seconds]
    [Time since reference or first frame: 0.000970000 seconds]
    Frame Number: 2
    Frame Length: 54 bytes (432 bits)
    Capture Length: 54 bytes (432 bits)
    [Frame is marked: False]
    [Frame is ignored: False]
    [Protocols in frame: eth:ip:vrrp]
Ethernet II, Src: 00:25:90:83:b0:07 (00:25:90:83:b0:07), Dst: 01:00:5e:00:00:12 (01:00:5e:00:00:12)
    Destination: 01:00:5e:00:00:12 (01:00:5e:00:00:12)
        Address: 01:00:5e:00:00:12 (01:00:5e:00:00:12)
        .... ...1 .... .... .... .... = IG bit: Group address (multicast/broadcast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Source: 00:25:90:83:b0:07 (00:25:90:83:b0:07)
        Address: 00:25:90:83:b0:07 (00:25:90:83:b0:07)
        .... ...0 .... .... .... .... = IG bit: Individual address (unicast)
        .... ..0. .... .... .... .... = LG bit: Globally unique address (factory default)
    Type: IP (0x0800)
Internet Protocol Version 4, Src: 10.0.10.11 (10.0.10.11), Dst: 224.0.0.18 (224.0.0.18)
    Version: 4
    Header length: 20 bytes
    Differentiated Services Field: 0x00 (DSCP 0x00: Default; ECN: 0x00: Not-ECT (Not ECN-Capable Transport))
        0000 00.. = Differentiated Services Codepoint: Default (0x00)
        .... ..00 = Explicit Congestion Notification: Not-ECT (Not ECN-Capable Transport) (0x00)
    Total Length: 40
    Identification: 0x8711 (34577)
    Flags: 0x00
        0... .... = Reserved bit: Not set
        .0.. .... = Don't fragment: Not set
        ..0. .... = More fragments: Not set
    Fragment offset: 0
    Time to live: 255
    Protocol: VRRP (112)
    Header checksum: 0x4037 [correct]
        [Good: True]
        [Bad: False]
    Source: 10.0.10.11 (10.0.10.11)
    Destination: 224.0.0.18 (224.0.0.18)
Virtual Router Redundancy Protocol
    Version 2, Packet type 1 (Advertisement)
        0010 .... = VRRP protocol version: 2
        .... 0001 = VRRP packet type: Advertisement (1)
    Virtual Rtr ID: 254
    Priority: 151 (Non-default backup priority)
    Addr Count: 1
    Auth Type: No Authentication (0)
    Adver Int: 1
    Checksum: 0x3c01 [correct]
    IP Address: 10.0.0.254 (10.0.0.254)

Best Answer

Related Solutions

Both servers running keepalived become master

KeepAliveD, Rackspace Cloud, Unicast – both LB’s enter MASTER state…

Related Topic