Hi,

I have application server on IP 10.10.220.42 (Prod).

When the Production goes down I wish to switch over all my application server's configuration files onto IP 10.10.220.45 (DR).

The client is exposed to proxy apache http webserver running @ IP 10.10.220.30

Can you please suggest what configuration change needs to go in where inorder to achieve Prod -> DR switch ?

What platform is this on? What hardware? What O/S?

Generally, you run some cluster/DR suite of software that manages failover. In those situations you might have node A and node B clustered. Node A is the production box and node B the DR box.

Both node A & B would have their "hardwired - never to change" IP addresses and the cluster suite presents a pseudo ip address to all clients. The clients only ever access this pseudo ip address (and don't know about the real ip addresses). When failover occurs the suite moves the pseudo ip address to the other node and the clients are none the wiser (apart from perhaps a few seconds hang).

So the question is; what have you got there?

This is very similar to what HACMP (IBMs failover software for AIX) does too. In HACMPs wording what you call "pseudo IP" is called "service IP" and technically it is an IP alias, which is moved with the "resource group" (a group of mounted file systems, start-/stop-scripts for the application and said IP address(es)).

I hope this helps.

bakunin

I need to do this on unix [Itanium] and windows[ignore Windows if this is not the correct forum].

The Prod to DR configuration files copying is done periodically [every 5 mins] by myself using crontab and scp.

Can you now help me with the exact steps ?

There is not so much "to do" - of course you can write such a high-availability system yourself. We will talk again a few years from now, probably....

What you have to do is to install such a high-availability software and form a cluster. There are several such software out there: HACMP, Veritas, Beowulf, NonStop-Cluster and probably a few dozen others. As you mentioned you run on Itanium i assume you have HP-Ux as OS, so you will probably need to install NonStop Cluster from HP.

I suggest you read up about "Failover-Clusters" and "active-passive clusters", as this is what you describe.

I hope this helps.

bakunin