RE: Hot Swap iSeries applications

["Graap, Kenneth" <Kenneth.Graap@xxxxxxxxxxxxx>]

> 1.Purchase a cluster-enabled software application 
> Software products that are cluster-enabled meet certain high-availability requirements.
 
> 2.Write or change your own application to make it highly available 
> Independent software vendors and application programmers can customize applications to allow them to be switchable in a >System i(r) clustered environment.

Charles, I believe the "key" to this whole thing is, a "cluster-enabled application".

This isn't an easy thing to do, especially if you have to retrofit an existing TN5250 application...

Notes from IBM:

Not every application will give you the availability benefits of clustering.
 
An application must be resilient in order to take advantage of the switchover and failover capabilities provided by clustering. Application resilience allows the application to be restarted on the backup node without having to reconfigure the clients using the application. Therefore your application must meet certain requirements to take full advantage of the capabilities offered by clustering.

Once you have a resilient application, it must be managed within your cluster.


Making application programs resilient
 

Learn how to make application programs resilient.
 
A resilient application is expected to have the following characteristics:
 *The application can be restarted on this node or another node
 *The application is accessible to the client through the IP address
 *The application is stateless or state information is known
 *Data that is associated with the application is available after switchover

Reply or Forwarded mail from: Kenneth E Graap

-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Charles Wilt
Sent: Tuesday, December 23, 2014 7:38 AM
To: Midrange Systems Technical Discussion
Subject: Re: Hot Swap iSeries applications

------------------------------
Cluster applications  (aka Planning Application Resiliency)

http://www-01.ibm.com/support/knowledgecenter/ssw_ibm_i_71/rzaig/rzaigapplications.htm?lang=en

On Tue, Dec 23, 2014 at 9:49 AM, Charles Wilt <charles.wilt@xxxxxxxxx>
wrote:

> May be too late...
>
> But I think "This technology just does not exist" is not correct.
>
> IBM i does support clustering...but the key is that your application 
> must support it also.  The term for this is "application resiliency".  
> I'm not sure if a 5250 application can be made resilient, but for 
> instance I'm pretty sure that SAP on the IBM i can be run in a clustered mode.
>
> Take a look here
> http://www.redbooks.ibm.com/redbooks/pdfs/sg247405.pdf
> http://www.redbooks.ibm.com/redbooks/pdfs/sg247994.pdf