Near-Zero Downtime Maintenance

nZDM for Software Update manager (SUM) is now general available

Since Software Update Manager (SUM) 1.0 SP7 which was released on April 9th the downtime optimization feature near-Zero Downtime Maintenance (nZDM) is general available.
After a very successful period of controlled projects on customer site all over the world this feature is now included in the Software Update Manager 1.0 (SUM). Until it was shipped with SP7 it has been used on customer side in app. 120 executions, 28 productively.

What do you have to invest?

There are no separate license fees for using the nZDM capabilities in SUM. SUM is contained in the SL Toolset and the newest version SP7 can be downloaded from the SAP Service Market Place.
This document describes the new available feature and the benefits you can expect regarding downtime optimization of SUM and will be regularly updated to keep you up to date.

Benefits of nZDM for SUM

In SUM you have the option to use one of the following pre-configurations:

• “Single System” =  no use of shadow instance (update) or shadow instance runs exclusively (upgrade)
• “Standard” = similar to EHPi or SAPup
• “Advanced” = intention to optimize the downtime

In SAP’s Software Update Manager (SUM) the advanced pre-configuration is used for extensive downtime optimization. So near-Zero Downtime Maintenance Technology (nZDM) is a new introduced option in the “Advanced” pre-configuration.

nZDM for SUM can be used for applying Support Packages, applying Enhancement Packages or upgrading an ABAP-based SAP Business Suite or SAP NetWeaver System.

Which improvement can be expected when nZDM is used in SUM? 

Based on the already made experiences on customer side nZDM for SUM enables a minimum downtime of around 2:30h – 3:00h. 
The overall technical downtime (= Minimum Downtime + Post-Processing) is reduced significantly although the post-processing phase is extended due to the nZDM feature to around 0:45h – 1:00h 
So in total we have an overall technical downtime of 3:15h – 4:00h

Just compare it with your key figures of your last update.

Please find below 4 examples from real customer projects and a comparison between the overall technical downtime with SUM without nZDM or EHPi and SUM with nZDM:

Thanks to high customer interest and close corporation we got a very good overview about working in different system environments and sizes.
Based on our experiences the technical downtime reduction seems to be stable and independent from database or data size as nZDM for SUM was tested by big customers as well.

The following measure shows an internal comparison between SUM for SAP ERP 6.0 with and without nZDM for SUM. 
Also in this example the technical downtime is reduced > 55%

Additionally you see that the overall project time is increased to app. 20-30%. This additional time is used during the phases running in uptime. This has to be considered in the update project planning. 
However the end-user realizes the wow-effect for sure when the downtime is reduced significantly! 
In the next step we plan to again reduce the business downtime with help of moving customer transports to the uptime phase. This near-zero downtime optimized feature is currently shipped on request.

Functionality

How does nZDM for SUM work?

The nZDM capability for SUM enables to run main parts of the Main_Import phase in the shadow.

Quick facts of nZDM for SUM:

• Introduction of "Record & Replay" technique for business transactions based on database trigger technology
• Minimizes manual effort: all steps run automatically in background
• Minimal additional hardware requirements due to shadow-technique, only additional DB space needed (80 – 350 GB)
• Is available for all ABAP-based Business Suite products

Record & Replay means that database changes during uptime of the maintenance process create triggers, which records the changes. The recordings are only needed for tables which are used for the update / upgrade in the shadow. With help of the recording the shadow tables will be updated after the upgrade/update phases in the uptime. The majority of the recording updates are run in the uptime. Only the delta (last 10%) has to run just before the switch in the downtime.

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

• DB2 LUW
• Oracle
• MS SQL
• DB2/zOS

In the coming weeks it is planned to release the nZDM feature also for MaxDB.

SUM allows 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

For further operational details please see note 1678564