Near-Zero Downtime

Near-Zero Downtime Maintenance for SAP Business Suite Systems

How to use the new build-in downtime minimization capabilities of Software Update Manager 1.0?

Since SP4 SAP’s Software Update Manager (SUM) is equipped with downtime minimization services in Standard or Advanced configuration setting  and additionally with the near-Zero Downtime Maintenance Technology (nZDM), to minimize the business downtime which occurs while applying Support Packages, applying an Enhancement Package or upgrading an ABAP-based SAP Business Suite or SAP NetWeaver System. This document describes the new feature and the procedure to follow in order to make use of the build-in near-Zero Downtime Maintenance capabilities of Software Update Manager and will be regularly updated to keep you up to date.

Summary

The Software Update Manager (SUM) has been extended with downtime minimization features since Support Package 4 (available since April 2012):

• Capabilities for extended downtime optimization in Advanced mode
• nZDM with "Record & Replay" technique for business transactions

The nZDM features address ABAP-based SAP Business Suite & SAP NetWeaver Systems and are currently available on request. Main reason is to have a controlled start phase of nZDM. With this it is possible to support the customers individually and get direct feedback. The experiences made in the last ½ year were very positive. Details about the registration process can be found in SAP note 1678565 “Prerequisites, Terms and Conditions for nZDM/SUM“.

As of now nZDM can be used for the following databases:

• DB2 LUW (SAP internal: DB6)
• Oracle

It is planned to extend the availability to all common database platforms in the next SPs (planned until SP7). Furthermore additional downtime improvements for SUM, e.g. integration of customer transports, are planned for next SP.

Experiences made with nZDM/SUM in SL Toolset SP4, SP5

nZDM/SUM has been successfully employed by around 20 customers with in total 44 executions. The executions were done on Sandbox, Development, Quality and Production systems. In total, the procedure has been executed on 12 productive systems so far with an average minimum technical downtime of 2:31 hours.

Compared to EHP installer the business downtime is reduced between 8 to 12 hours.

Which improvement can be expected when nZDM is used in SUM? In the following example you see the difference between SUM without nZDM and SUM with nZDM. 

Based on our experiences with customer implementations the technical downtime reduction seems to be stable and independent from database or data size as nZDM/SUM was tested by big customers as well.

More details about the nZDM/SUM Capabilities

nZDM/SUM is designed to apply Enhancement Packages, run upgrades or updates of SP’s for the ABAP components of the SAP Business Suite Optimization of updates/upgrades of Java components are investigated at the moment.

SUM will allow using the nZDM capabilities for the following standard software maintenance activities:

• Apply a Support Package on any ABAP-System with a target release based on SAP NetWeaver 7.0 Enhancement Package 2, SP8 or higher
• Install an Enhancement Package on top of any ABAP-System with a target release based on SAP NetWeaver 7.0 Enhancement Package 2, SP8 or higher
• Upgrade your system to any ABAP-System with a target release based on SAP NetWeaver 7.0 Enhancement Package 3 or higher

The main benefit of nZDM/SUM is the significant reduction of the technical downtime compared to previous update and upgrade tools, because more relevant update or upgrade phases are executed while the system is still up and available for business users:

Main former downtime activities which are executed during uptime in nZDM/SUM:

• Load generation (SGEN)
• Selected long-running After Import Methods
• Mass-generation of Enhancement Objects, Generation of Enqueue Objects
• Table structure adjustment incl. conversions (based on Record & Replay technique)
• Main import (based on Record & Replay technique)
• Customer transports (planned with next SP)

This leads to a significant reduction of business downtime (in average more than 10 hours compared to former standard maintenance tools).

Overview Standard procedure vs. downtime optimized procedure in SUM:

The execution of the additional shadow operations becomes possible by introducing the “2nd shadow instance”. This second shadow instance is an evolution of the already existing shadow that reflects the fully consistent target state of the system according to the selected stack.
Due to this, some activities can be pre-poned and are possible during uptime.

With the introduction of record and replay techniques in nZDM/SUM it becomes possible to capture database changes on the production instance during uptime. This allows importing new content into the shadow while all users are still able to work on the production system. The captured changes are transferred to the shadow iteratively after the import has been finished.

A final delta replay in downtime is still necessary but the volume is typically very small.

Due to extended shadow system the post-processing phase of the technical downtime will be increased to app. 30 - 45 minutes. This time is needed to finally clear the shadow.

Of course, nZDM is embedded in SUM. In future it is planned to have it select-able and visible in the guided procedures and also visible in the phase reporting and log files.

What do I need to invest and how do I get it?

There are no separate license fees for using the nZDM capabilities in SUM. SUM is contained in the SL Toolset 1.0 and can be download from the SAP Service Market Place. The advanced procedures in the SUM are already available

Which additional system resources are required?

For SUM with nZDM app. 350 GB temporary space for database and file system are required. All shadow operations happen in the same System (same SID), it is NOT a clone copy.

The nZDM-capabilities of SUM/SP4 or higher are not generally released yet. However, SAP offers interested customers and partners to use this new SUM feature nZDM/SUM on an “Available on Request” basis.

Based on this “Available on request” approach we ensure the best support (SAP Back Office ) from our side and ensure that the customer feedback is considered in our development activities and finally you can even use it in a productive environment. As already mentioned this approach has been already used by about 20 customers.

So, if you want to make use of this feature right now, you can use them and even go live with this You just will need to register your project in the related SAP Development Team, that in turn will enable you to activate the features and to benefit from direct SAP Back Office support. The latest description about the procedure is described in detail in SAP note 1678565 “Prerequisites, Terms and Conditions for nZDM/SUM“. In short, the process looks like this:

1. Open a support ticket under component "BC-UPG-OCS-NZDM". The ticket header should contain the following Title: "[nZDM/SUM]: Request for registration". Within the long text of your support ticket please provide necessary information about your system’s architecture and contact data.
2. The SAP Back Office will get back to you in order to clarify all necessary aspects of the feature activation and execution of the software. Depending on the number of requests in the pipeline, the point in time, when SAP Back Office is able to support you using this feature need to be clarified with the SAP Back Office.
3. SAP Back Office will provide you with documentation how to activate the nZDM feature of SUM and how to make use of it during the supported software maintenance activities.
4. SAP Back Office will provide support in case of errors in the procedure. Any open questions and/or problems, which may occur during the preparation and execution of the maintenance process, should be addressed via a regular support ticket on a dedicated application component in order to quickly bypass regular support line and get processes by the Back Office instance.

Any feedback regarding functionality and usability is also highly appreciated