A New Developer’s Guide for Session Failover Enabled Java EE Applications

[Vanya]

Do you know how to leverage the session failover capabilities of the SAP NetWeaver Application Server Java? Do you know how to make your applications failover-safe? Now there is a new Developer's Guide explaining how to do this in SAP NetWeaver CE and PI 7.1.

The architecture of SAP NetWeaver Application Server Java provides flexible mechanisms for enhanced control of sessions and smooth and transparent failover in case of a server crash. Software developers, quality assurance specialists and system administrators can easily utilize these new advanced session failover capabilities. You can now chose failover strategies and storage types depending on your use case, as well as additional tools (such as Telnet commands), which enable appropriate configuration and debugging.

In "Session Failover for Java EE Applications - Developer's Guide", you can find the basics of AS Java session failover as well as guidelines on how to enable this functionality for applications and to configure your systems for failover. For more information: http://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/7073bb46-2ede-2b10-189c-8bfd09a0c...

[Former Member]

I've found the "Session Failover for Java EE Applications – Developer’s Guide" document very useful.  Wondering if there are any differences between using simulation mode versus the SAP Web Dispatcher?  In other words, is there any functionality that's not tested by simulation mode that might impact how our application would work in a real clustered environment?

Thanks,
William

[Vanya]

Hi William,

Thank you for your feedback and question.
The simulation mode is intended to test ONLY if the application session is failover enabled all the time.
It is not 100% emulation of "real clustered environment", so there is no guarantee that the behavior of the application itself will be the same.
I hope that answers your question.

Thanks,
Vanya

[Former Member]

<br/>The documentation for the NWCE 7.1 deployment descriptor shows this DTD (http://help.sap.com/saphelp_nwce10/helpdata/en/45/053c1041f30486e10000000a155369/content.htm):<br/>  <fail-over-enable<br/>    mode="on_request"<br/>    scope="cluster_wide"/><br/>But when we use it the ear/sda doesn't deploy.<br/><br/>This document (https://www.sdn.sap.com/irj/scn/index?rid=/library/uuid/7073bb46-2ede-2b10-189c-8bfd09a0c95e&overrid...) shows this DTD:<br/><fail-over-enable<br/>mode="on_request"<br/>delta="on"<br/>xsi:type="fail-over-enableType_enable"/><br/>But, it doesn't deploy unless we leave out the delta attribute.<br/><br/>Should this be the case?  Should we open a Support Message since the product documentation is wrong?<br/><br/>Thanks,<br/>William<br/>

[Vanya]

Hi William,

We're now investigating the issue with development colleagues and will give you the answer soon.
In the meantime, I'd like to let you know that you can now add similar comments to the SAP NetWeaver CE 7.1 EHP1 product documentation and even edit it yourself directly in a documentation wiki - docupedia: https://cw.sdn.sap.com/cw/community/docupedia/nwce71ehp1?view=overview

Thanks for the feedback and talk to you soon.
Best regards,
Vanya