Skip to Content
avatar image
Former Member

Jco Destinations for aliases

We have a Java web dynpro on one host in it's own instance that calls data from an ERP ABAP system on another host as another instance. Our entire landscape is HA, where the apps all call each other by the alias. We can fail any instance to site B along with the respective DNS entry and the other intances (ABAP) can continue accessing the failed over host by alias with a simple 'hostname buffer refresh' in SM50.

But with the web dynrpo, we get our system info from the SLD, which has the actual host names listed. We use RZ70 on the respective system(s) to pass info to the SLD, so it's not using the alias that is defined in the system profile, but instead the actual host name.

So when we failed over the ERP ABAP system, our web dynpro was unable to find it until we deleted the MetaRFC Jco Destination and recreated it with the correct real host name (the SLD already updated itself with the new hostname in the nightly job).

This is very limiting and makes a failover scenario more difficult and adds a manual step. How could we make sure that the SLD transfer from an ABAP system use the alias as defined in the system profile?

Add comment
10|10000 characters needed characters exceeded

  • Get RSS Feed

1 Answer

  • avatar image
    Former Member
    Feb 05, 2007 at 08:22 PM

    One other issue is that, with the RFC Metadata JCo destination, we have to re-enter the credentials we have hard coded there. Using a SSO certificate is not an option here because this is not the transactional RFC. We cannot simply edit this connection without having to re-enter the pwd to the static user (service user on the ERP ABAP side).

    Add comment
    10|10000 characters needed characters exceeded

    • Former Member

      Bumping this back up. I got a response from SAP Support that was basically one sentence:

      "what you wish to achieve is not possible."

      So I want to see what others have done here in the above scenario. To summarize it better:

      HA environment J2EE and ABAP instances, both with their own primary host A and failover host B. They are each accessed via their own alias 'hostC'.

      SLD running on J2EE instance gets updates from ABAP system via job setup in RZ70. This passes the ACTUAL host name(host A), although the alias (host C) is defined in the ABAP system profile.

      J2EE web dynpro calls backend data via JcoDestination, which is predictated on SLD host name info.

      When we have a hardware failover of only the ABAP instance, the SLD is not updated until RZ70 job is run again (automatically or manually). But even then, the Web Dynpro has the OLD (ABAP host A) defined in the JCODestination. We have to manually recreate the destination where the pull down menu of hosts allows us to pick the failedover host (host B).

      SAP says there's no way to force the ABAP/RZ70 job to send the alias as defined in the system profile. If it could, then the SLD would pick that up and the JCO Destination would have it, and the web dynpro that uses that JCO Destination would still function without all this manual intervention.

      Does anyone have any suggestions? This is a severe shortcoming of using an application that relies on SLD info in a HA environment that uses host name aliases.