Fwd: How to change the names on Load Balancers

[Horms <horms@xxxxxxxxxxxx>]

Hi James,

thanks for this. I have taken the liberty of forwarding your
message to the linux-ha list as it is relevant to heartbeat,
and the linux-ha list is the home of discussion of that software.

Thanks again

-- 
Horms

----- Forwarded message from James Bromberger <jbromberger@xxxxxxxxxxx> -----

To: lvs-users@xxxxxxxxxxxxxxxxxxxxxx
From: James Bromberger <jbromberger@xxxxxxxxxxx>
Date: Tue, 22 Jun 2004 12:32:56 +0100
Subject: How to change the names on Load Balancers
Reply-To: "LinuxVirtualServer.org users mailing list." 
<lvs-users@xxxxxxxxxxxxxxxxxxxxxx>
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        version=2.63-vergenet_2004061103

Hi all.

We're using UltraMonkey (ldirector and heartbeat) on a pair of hosts. 
As they were being added in to replace an older pair, we called them by 
some temporary names ('oldhostname-A-new' and 'oldhostname-B-new') as 
we eased them in. Now we needed to change their names (to the hosts 
they replaced), but since hostnames are used in HA setup, there is a 
procedure to get this done with no downtime. Here is what we have just 
done, posted just to add to collective knowledge (unless someone has 
already posted this or it is a FAQ, in which case I am sorry for the 
noise):


Overview: host A needs to become host C and B needs to become host D.


A: Make A (host that will become C) active load balancer: hb_takeover.

B: /etc/init.d/heartbeat stop; vi /etc/ha.d/ha.cf
        # add an entry for C and D so 4 hosts are listed

B: /etc/init.d/heartbeat start

B: hb_takeover

A: /etc/init.d/heartbeat stop; vi /etc/ha.d/ha.cf
        # add an entry for C and D so 4 hosts are listed

A: /etc/init.d/heartbeat start

A: hostname C
        # changes the first host's name, don't forget to update 
        /etc/hostname to C

A: hb_takeover

B: /etc/init.d/heartbeat stop; vi /etc/ha.d/ha.cf
        # remove A and B leaving only C and D

B: hostname D
        # changes the second host's name, don't forget to update 
        /etc/hostname to D

B: /etc/init,.d/heartbeat start

B: hb_takeover

A: /etc/init.d/heartbeat stop; vi /etc/ha.d/ha.cf
        # remove A and B leaving only C and D

A: /etc/init.d/heartbeat start

A: hb_takeover
        # Leave host A as the active load balancer, if you wish



(BTW, really impressed with the speed of takeover, less than half a 
second I think, and no packets dropped with shared connection state via 
ipvs_syncbackup and ipvs_syncmaster running on both nodes! Excellent!).


Regards,
  James

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----- End forwarded message -----