User experience question for High Availability

Question

Hi Experters,
Not sure whether this is right forum to post this message.
If anybody has already captured user experience for the failover environment, will appreciate their help on this. I will give overview of environment. Using PowerHA for ASCS/SCS failover, ORACLE Data Guard for Database failover.
Trying to capture user experience for the failover environment
if ASCS/SCS fail,
App Server Fail (using F5 Load Balancer which should reroute, unless all app server fail),
Database fail
with following cases:
1. User logged in, NO ACTIVITY. I believe NO IMPACT either ASCS/SCS fail or DB fail or App Server fail.
2. User logged in and run a transaction before failover.
     What will happen in case of ASCS / SCS
     What will happen in case of DB failover
   and  what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
3. User logged in and run a transaction during failover.
   What will happen in case of ASCS / SCS
     What will happen in case of DB failover
   and  what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
Not sure which one possible or not. Some case thinking system will hang need to refresh. Some case hour glass and then come back once failover complete. and some case session closed completely.
Thanks for your time and god bless the knowledge you have.
Saroj

Answer 1

just try to answer as much as I can (guess)
> 1. User logged in, NO ACTIVITY. I believe NO IMPACT either ASCS/SCS fail or DB fail or App Server fail.
DB failed and SCS failed won't have any impact to enduser, but if app server failed, the user session will lost, user will see a pop up error message at their SAPGUI.
> 2. User logged in and run a transaction before failover.
>      What will happen in case of ASCS / SCS
user wont'be effected during failover if user is doing nothing but idle (replica enqueue is working before failover)
>      What will happen in case of DB failover
App server won't be able to do much thing but it's work processes into reonnecting status. it should resume (reconnect to DB) when failover is compoleted. So user should be able to continue the sessions.
>    and  what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
user sessions in failed app server will be lost. However user should be able to logon agan if
1)  logon via group, and
2) within the group, there is at least one appl server alive.
> 3. User logged in and run a transaction during failover.
hanging or
>    What will happen in case of ASCS / SCS
if the transaction is using enqueue service, for example, then user will get error message.  otherwise, user won't be effected, e.g. if use is just search a list of order. user wont to able to logon via group during the failover.
You also should be pepared for user connected through message server, .e.g. http request dispatching through message server directly , or via web dispatchr. user wont be able to connect during the failover.
>      What will happen in case of DB failover
user will get error message, transaction will be aborted.
>    and  what will happen in case of App server fail (NO High Availability, only redundant app servers.      MAX 4 app servers for each component)
very similar case  as case 2.