How to create a virtual IP/hostname for a 2 nodes cluster

[Art Wildman]

Herta Van den Eynde wrote:
> You're right of course, crypto, LVS is the Red Hat load balancer.  (I
> usually call it piranha, hence my mistake.)  The description I was
> giving is for the failover cluster software.  (Does that even have a
> name?)

Linux HA - HighAvailability - Heartbeat Package
http://www.linux-ha.org/ConfiguringHeartbeat

Howtoforge.com has a number of howtos on configuring different services
for heartbeat & failover.
http://www.howtoforge.com/high_availability_heartbeat_centos
http://www.howtoforge.com/high_availability_loadbalanced_apache_cluster
http://www.howtoforge.com/high-availability-load-balancer-haproxy-heartbeat-fedora8
http://www.howtoforge.com/high_availability_nfs_drbd_heartbeat
http://www.howtoforge.com/loadbalanced_mysql_cluster_debian

-HTH Art at JAX

>
> So Amos, just to understand your requirements better, does your
> active-active cluster run all three services on both nodes, or does it
> run one service on one cluster member and the remaining two on the
> second cluster member?
>
> Kind regards,
>
> Herta
>
> 2009/8/14 crypto grid <cryptogrid at gmail.com <mailto:cryptogrid at gmail.com>>
>
>     On Wed, Aug 12, 2009 at 10:14 AM, Herta Van den Eynde
>     <herta.vandeneynde at gmail.com <mailto:herta.vandeneynde at gmail.com>>
>     wrote:
>
>         As this is only a two node cluster, why would you add a load
>         balancer?
>
>      
>     AFAIK, LVS is, indeed a load balancer. There is no way you can run
>     an a-a service in the cluster without a balanced ip.
>      
>
>
>
>         LVS will give you a unique ip-address per service that you are
>         running in the cluster.  I.e. in your case, you'll get 2 fixed
>         ip-addresses (one for each server) and three virtual addresses
>         (one for each service).
>         When one of the servers goes down, the services (including the
>         virtual addresses) running on that server will automatically
>         migrate to the other server.
>
>      
>     I saw some customers who didn't want to install red hat lvs in
>     their clusters. Instead, they insisted to use external
>     loadbalancers, and personally, I have no objection with that,
>     because in some way, you are taking some "complexity" out of the
>     servers.
>     Sorry for going off at a tangent.
>      
>
>
>
>         There are a number of caveats, though. 
>         1. you need central storage and a cluster-aware filesystem
>         2. when services fail over to the other node (either because
>         of server failure or manually), the services are stopped (or
>         crash) on the first server and are restarted on the second. 
>         I.e. running processes do not continue running.  I.e. your
>         applications (and end-users) have to know that when your
>         database fails over, they will have to reconnect.
>
>         I have no experience with Oracle iAS, or E-business Suite 11i,
>         but if you want to cluster Oracle databases, Oracle RAC (Real
>         Application Cluster) is the way to go. 
>         Undoubtedly, Oracle can at least let you know the best way to
>         add redundancy for Oracle iAS and E-business Suite 11i.
>
>         Kind regards,
>
>         Herta
>          
>
>         2009/8/10 crypto grid <cryptogrid at gmail.com
>         <mailto:cryptogrid at gmail.com>>
>
>             For an active/active mode, i'd recommend the use of a load
>             balancer in
>             the frontend and the use of private per service ip
>             addresses in the
>             backend for each node in the cluster.
>             Give a look at,
>             http://www.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/Virtual_Server_Administration/
>
>             I think you could use LVS in the same cluster nodes.
>
>             On 8/10/09, Amos KABORE <amos.kabore at gmail.com
>             <mailto:amos.kabore at gmail.com>> wrote:
>             > Hello,
>             >
>             >
>             >
>             > We have 2 nodes cluster with rhel5.
>             >
>             > Luci is used to manage our cluster (active/active).
>             >
>             >
>             >
>             > Our system includes 3 services (Oracle iAS, Oracle
>             database and E-business
>             > Suite 11i).
>             >
>             > We want to create a unique virtual IP/hostname for these
>             services.
>             >
>             > Is it possible ?
>             >
>             >
>             >
>             > How to create a virtual IP/Hostname in our case ?
>             >
>             >
>             >
>             > As I'm to new to cluster world, your help will be precious.
>             >
>             >
>             >
>             > Thanks
>             >
>             >
>             >
>             > amos.kabore at expercosarl.com
>             <mailto:amos.kabore at expercosarl.com>
>             >
>             >
>             >
>             >
>             >
>             >
>
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