SAP Technical Upgrade Essentials and considerations
Upgrade Driving Factor:
SAP version / Enhancement Pack upgrade generally required on below scenario:
- Maintenance support of SAP Version is getting over from SAP.
- New functionalities needs to be implemented which can be delivered in upgraded version of SAP.
These are the primary driving factor for any SAP Upgrades.
Planning, Pre-requisite and Prior activities:
Following consideration is required for any successful upgrade within feasible timeline:
- Infrastructure (Hardware) compatibility with new version of SAP.
- Detailed study on platform (OS/DB) adaptability with newer SAP Version.
- Analysis of overall SAP Landscape for dependencies on other SAP & Non SAP applications.
- Explore possibility of Archiving prior to any version upgrade this will reduce the additional infrastructure requirement as well as downtime during the upgrade process.
- Analyse SAP System application critically and database size to plan upgrade strategy.
Infrastructure and platform study needs to done using the SAP product availability matrix (PAM). Using SAP PAM we can check the availability of newer SAP on specific OS and Database version. Below attached is the sample screenshot of SAP PAM (https://service.sap.com/pam).
To know any upgrade dependencies between systems in SAP landscape SAP UDA online tool can be used to check SAP component dependency. SAP UDA tool is accessible via two ways:
- SAP Service Marketplace: http://service.sap.com/uda
- SAP Solution Manager.
This will help in:
- Identifying existence of upgrade dependencies between two separately installed SAP systems in Customer’s SAP system landscape
- High level technical planning
- Shows known dependencies on technical level according to categories:
- Dependency exists
- Conditional dependency exists
- Currently no dependencies
Below sample dependencies can be generated using SAP UDA tool.
Using above results we can develop phasing concept in upgrade phase. We need carry out an analysis of the systems to be upgraded to determine the inter-dependency between the various system components to be upgraded. Sample analysis is highlighted below:
The outcome of the mapping will help in identifying the systems which are not dependant on the others, and hence theoretically can be upgraded on a separate track independently.
SAP Upgrade Tools and Upgrade strategy
SAP Software Update Manager (SUM) is a multi-purpose tool, which supports following processes related with Upgrades:
- Performing a SAP release upgrade
- Installing SAP enhancement packages
- Applying Support Package stacks (SPS)
The Software Update Manager checks the consistency of planned change and technical system where the change should be applied.
The current version of the Software Update Manager replaces well-known tools for SAP enhancement package implementation and upgrade
SUM Key Features Includes:
- Improved user experience and unified capability
- Transparency about source system state, installed products and content to be updated.
- Overview of process details upon and after SUM procedure.
- Extended prerequisite checks to optimize the stop and start procedure of instances.
- Higher degree of parallelization for certain phase types to overall runtime reduction.
- Downtime Reduction using Enhanced Shadow System capabilities :
- Execution of selected After Import Methods
- Mass-generation of Enhancement Objects
- Generation of Enqueue Objects
- Load generation in shadow system during uptime.
Deciding Upgrade strategy
The upgrade strategy is one of the main factors in determining how much downtime is involved. The SAP SUM tool offers following two update strategies :
Downtime minimization strategy using shadow instance technique of SAP’s Software Update Manager (SUM) tool is used to reduce the downtime during the Upgrade process. The Process overview report generated from SUM Tool during Test and Pre-Prod upgrades will also help in estimation of downtime required during the production upgrades.
Following are the major consideration of downtime minimization:
- Parallel operation of production system and shadow system
- Use of shadow instance for the main import in the “advanced” pre-configuration mode.
- Import of the substitution set into the shadow tables during production operation
- Intensive use of parallelization for Batch processing, DDL processes and R3TRANS.
- Modification adjustment of the ABAP Dictionary objects during production operation
- Activation and distribution during production operation
- Production operation stops in phase DOWNCONF_TRANS
- SGEN in the shadow instance.
- Customer transports (on request)
SAP SUM tool provides standard & advance options for Downtime Minimization based upon the shadow instance process:
Below depicted diagrams are showing the in-built features of SAP SUM tool on up-time and downtime period during the exection of
upgrade process using Standard and advance optiions of SUM tool.
SUM Standard Option for Downtime Minimization :
Below diagram discribes uptime and downtime processes in standard downtime minimization option of SUM tool.
SUM Advance Option for Extensive Downtime Minimization:
Below diagram discribes uptime and downtime processes in advance downtime minimization option of SUM tool.
Temporary increase of approx. 10%. in CPU & RAM and additional DB Storage of around 20-25% will be required for Shadow-technique to minimize downtime. However this needs to be analysed during the assessment/preparation phase of the project.