[SOLVED] ucarp

pingu · 09-11-2013, 10:16 AM

When 2 servers share an ip with ucarp, how an I see which one is active?
I'm running mysql-5.6 on two Centos 6 servers.
Mysql is configured master-master, and ucarp is used for failover. This works fine.
But sometimes I want to know which server is active, can't see how to check that?
'ifconfig' only shows each servers "own" adress, not the virtual ip.
'netstat' doesn't give any hint.

nini09 · 09-11-2013, 02:40 PM

The "ifconfig" should give a clue. If one of two server show like following, that is active. The IP address of interface is virtual and the interface has a alias name.

eth1:ucarp Link encap:Ethernet HWaddr 00:0c:29:5b:d8:03
inet addr:172.17.0.74 Bcast:172.17.15.255 Mask:255.255.240.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1

pingu · 09-13-2013, 03:23 AM

Thanks, but as I wrote:
"'ifconfig' only shows each servers "own" adress, not the virtual ip."

nini09 · 09-13-2013, 02:42 PM

Do you configure VIP_INTERFACE="eth0:0" option?

pingu · 10-07-2013, 04:20 AM

Sorry for late reply.
No, I have not configured eth0:0

I tried adding
"VIP_INTERFACE="eth0:0"
"BIND_INTERFACE="eth0:0"
to the config file, but ifconfig still shows nothing.
I had hoped I could use the simple default config but I guess I have to add configuration for eth0:0 and change startup.

pingu · 10-07-2013, 04:27 AM

Found it!
Instead of using "ifconfig" i tried "ip addr", this command shows the carp address on eth0!

Code:

# ip addr
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:00:00:00:00:00 brd ff:ff:ff:ff:ff:ff
    inet 172.17.1.12/24 brd 172.17.1.255 scope global eth0
    inet 172.17.1.9/32 scope global eth0
    inet6 fe80::216:3eff:fe30:bb98/64 scope link 
       valid_lft forever preferred_lft forever