System Upgrade | Part 2 : Zero Down Time Readiness Process

Step 1 : Content Migration for SAP HANA

The old repo of SAP HANA 1.0 stores calculation views ( native artifacts : to create and access native database objects ) in a singleton schema _SYS_BIC which is not zero downtime compliant

Future Scope is to ship the above native artifacts of SAP HANA will be shipped in HDI Containers to be zero downtime ready

Several areas in SAP S/4HANA have already provided reports to migrate native content of SAP HANA from Repo of SAP HANA 1.0 to HDI containers.

Summary from the above mentioned 3 points would be that native artifacts that were used to create or access native database objects are not supported by ZDO and are migrated to HDI containers to make them compatible for the same

All changes performed by SUM in ZDO need to be invisible to the user in the bridge sub system . The repo 1.0 in SAP HANA (native artifacts) does not have the capability to encapsulate the changes during ZDO upgrades.

Since SAP S/4HANA 1709 FPS 02 ,comes with the new way to store the calculation views native artifacts to Hana Deployment Infrastructure which fully supports zero downtime maintenance. Point to note and understand here that HANA Deployment infrastructure was introduced in SAP S/4HANA 1709 but ZDO generally available from S/4HANA 2020.

One line summary : To use ZDO , all the create and access database objects which were initially in native artifacts should be shifted to HDI . This migration is required before going up with the ZDO approach of upgrading.

Step 2 : ZDO compliance and enablement

If we need to follow this approach , strict development guidelines for ZDO should be followed by the developers. These changes in software are delivered in upgrades and update that can be critical :-

Structural changes to the persistence layer.
Delivering new transport changes linked to After Import Methods (AIM)
New Application defined procedure like AIM or XPRA programs.To identify the tables that are accessed when running these functions, methods, and reports in phase XPRAS_AIMMRG.
Within SAP , all development systems are connected to ABAP test cockpit (ATC) which considers ZDO. When it runs against the ATC check with focus on ZDO compliance
Not Only changes of database object (that should be in HDI) , but also new development of application defined procedures like After Import Method or new XPRA program should follow ZDO
Proper encapsulation is required for source and target release, this is achieved by knowing every table that is either changed or accessed by the upgrade
ZDO enablement of application-defined procedures contains the meta-data information on tables accessed when executing the source code.
In case a ZDO enablement is missing , the vendor can ship the enhancement with the upcoming support pack . ZDO enablement is also shipped with new patch levels of Software Update Manager.
In exceptional cases, complex changes might be shipped for certain applications. These complex changes can have an impact in the application during the ZDO upgrade.

Step 3: ZDO Table Classification

Key Principal : Encapsulate the Source and Target Release

To achieve that as already mentioned in Step2 [Point 6] , knowing every table that is either changed or accessed by upgrade tool.

RUN_RSPTBFIL_ZDM_CLASSIFY : This automated process is triggered and completely handled by SUM.

Image Source : The SAP official ZDO training book CA330

Step 4 : Impact Analysis of SUM

ZDO can have certain impacts on ongoing business operations on the bridge subsystem. Depending on which tables are accessed and at what frequency. To prevent unexpected occurrences of such impacts during the maintenance event on our prod system we have a check in advance.

“what would happen if the defined upgrade scope would be applied in the production system?”

First we run in sandbox with no business user , thus we need not focus on that and production we have business user who will be accessing few table and we should just be aware of the effects it should make.

Step 5 : Silent Data Migration

With SAP S/4HANA 1909 , SAP introduced a new framework to deliver a simplification of data models in event of Zero Downtime Option. Allows the developers to decouple the data model changes of a business application from functional change. While after an upgrade runs on target version the old data model is still compatible with the new application (Both old and new data models are allowed to use)

Stay tuned for more post on zero down time approach

Comments

You might find these interesting

How to properly Start/Stop SAP system through command line ?

Starting/stopping an SAP system is not a critical task, but the method that most of us follow to achieve this is sometimes wrong. A common mistake that most of the SAP admins do is, making use of the 'startsap' and 'stopsap' commands for starting/stopping the system. These commands got deprecated in 2015 because the scripts were not being maintained anymore and SAP recommends not to use them as many people have faced errors while executing those scripts. For more info and the bugs in scripts, you can check the sap note 809477. These scripts are not available in kernel version 7.73 and later. So if these are not the correct commands, then how to start/stop the sap system? In this post, we will see how to do it in the correct way. SAP SYSTEM VS INSTANCE In SAP, an instance is a group of resources such as memory, work processes and so on, usually in support of a single application server or database server with

sapstartsrv is not started or sapcontrol is not working

What is sapstartsrv ? The SAP start service runs on every computer where an instance of an SAP system is started. It is implemented as a service on Windows, and as a daemon on UNIX. The process is called sapstartsrv.exe on Windows, and sapstartsrv on UNIX platforms. The SAP start service provides the following functions for monitoring SAP systems, instances, and processes. Starting and stopping Monitoring the runtime state Reading logs, traces, and configuration files Technical information, such as network ports, active sessions, thread lists, etc. These services are provided on SAPControl SOAP Web Service, and used by SAP monitoring tools (SAP Management Console, SAP NetWeaver Administrator, etc.). For more understanding use this link : https://help.sap.com/doc/saphelp_nw73ehp1/7.31.19/enUS/b3/903925c34a45e28a2861b59c3c5623/content.htm?no_cache=true How to check if it is working or not ? In case of linux , you can simply ps -ef | grep sapstartsrv In case of windows, you need

HANA System Replication - Prerequisites & Setup

Hey Folks! Welcome back to Hana high availability blog series. In our last blog we checked out operation & replication modes in hana system replication. If you haven't gone though that blog, you can checkout this link In this blog we will be talking about the prerequisites of hana replication and it's setup. So let's get started. When we plan to setup hana system replication, we need to make sure that all prerequisite steps have been followed. Let's have a look at these prerequisites. HANA System Replication Prerequisites: Primary & secondary systems should be up & running HDB version of secondary should be greater than or equal to Primary database sever But, for Active/Active(read enabled config), HDB version should be same on both sites. System configuration/ini files should be identical on both sides Replication happe

ST03N : The chapter for all BASIS Admins

This blog is targeted to BASIS ADMINS Transaction for workload analysis statistical data changed over time are monitored using transaction code ST03 , now ST03N (from SAP R/3 4.6C) . With SAP Web AS 6.4 the transaction ST03 is available again. From time to time ST03 and ST03N has seen many changes but later in SAP NW7.0 ST03N has reworked in detail specially processing time is now shown in separate column. Main Use of ST03N is to get detailed information on performance of any ABAP based SAP system. Workload monitor analyzes the statistical data originally collected by kernel. You can compare or analyze the performance of a single application server or multiple application server. Using this you start checking from the entire system and finding your way to that one application server and narrowing down to exact issue. By Default :- You see data of current day as default view , you can change the default view. Source of the image : sap-perf.ca Let's discuss the WORKLOAD MONITOR By D

HANA hdbuserstore

The hdbuserstore (hana secure user store) is a tool which comes as an executable with the SAP Hana Client package. This secure user store allows you to store SAP HANA connection information, including user passwords, securely on clients. With the help of secure store, the client applications can connect to SAP HANA without the user having to enter host name or logon credentials. You can also use the secure store to configure failover support for application servers in a 3-tier scenario (for example, SAP Business Warehouse) by storing a list of all the hosts that the application server can connect to. To access the system using secure store, there are two connect options: (1)key and (2)virtualHostName. key is the hdbuserstore key that you use to connect to SAP HANA, while virtualHostName specifies the virtual host name. This option allows you to change where the hdbuserstore searches for the data and key files. Note

How to resolve Common Error : Standard Template "sap_sm.xls" missing

Hey everyone, putting forward a common error we usually face when we have “ Excel inplace” functionality enabled in our SAP system. This error occurs when validity of the signature of SAP standard templates expired or were incorrectly delivered via support packages. We can reproduce the error by doing as below.. Click on “spreadsheet” icon after any SAP ALV grid view of data is on screen to make this data to export into excel directly from SAP.

Work Process and Memory Management in SAP

Let’s talk about the entire concepts that are related to memory when we talk about SAP Application. Starting with few basic terminologies, Local Memory : Local process memory, the operating system keeps the two allocation steps transparent. The operating system does the other tasks, such as reserving physical memory, loading and unloading virtual memory into and out of the main memory. Shared Memory : If several processes are to access the same memory area, the two allocation steps are not transparent. One object is created that represents the physical memory and can be used by various processes. The processes can map the object fully or partially into the address space. The way this is done varies from platform to platform. Memory mapped files, unnamed mapped files, and shared memory are used. Extended Memory : SAP extended memory is the core of the SAP memory management system. Each SAP work process has a part reserved in its virtual address space for extended memory. You can set

Complete Guide : XPI Inspector Tool

Content of this blog : What is an XPI Inspector Tool ? Why XPI Tool is used ? XPI standard URL How to check XPI Tool version ? How to Install/Update XPI version using TELNET How to Use XPI Tool ? References – SAP Notes What is XPI Inspector tool ? - XPI Inspector is a diagnostics web application developed by SAP that collects logs and debug traces from various PI components in a very simple way and is useful for SAP PI consultants, developers, and administrators to get more insights on an issue. Why XPI is used – 1. Used to collect traces and logs from Messaging system or XI module. 2. Used to collect the related information to solving the issues or improving the PI or PO systems’ performance. 3. Using XPI Inspector application you will be able to collect a lot of information about your system that will help you to learn about problems in the past, to analyze new and detect such at an early stage. 4. Performs certain number of configuration checks, such as SSL c

ABAP Dumps Analysis

Ever now and then have you heard about ABAP Dumps, We also have a joke everything in temporary in life except ABAP dumps for SAP Consultants. Lets try to understand ABAP dumps from perspective of a SAP BASIS Consultant. Dumps happen when an ABAP program runs and something goes wrong that cannot be handled by the program We have two broad categories of Dumps , In custom program Dumps and SAP provided program Dumps. Dumps that happen in the customer namespace ranges (i.e. own-developed code) or known as Custom Program , can usually be fixed by the ABAP programmer of your team. Dumps that happen in SAP standard code probably need a fix from SAP. You do not have to be an "ABAPer" in order to resolve ABAP dump issues. The common way to deal with them is to look up in ST22 How to correct the error ? Hints are given for the keywords that may be used to search on the note system. Gather Information about the issue Go to System > Status and Check the Basis SP level as well as info

SAP system migration blog series - part 1: migration overview

Summary : This blog is part 1 of the blog series on SAP system migration. In this blog, we will provide overview about SAP migration, types of migration, their differences and usage scenario. SAP migration overview : As the Greek philosopher, Heraclitus, said: “change is the only constant.” Same goes within SAP world too, often customer have to change the SAP systems along with its underlying components to meet the changing requirements, be it change from old hardware to new one, changing operating system, database. This change in SAP system components (DB, OS or Hardware) is termed as migration. Before we go into details of migration, let’s understand architecture of a typical SAP system. An SAP system consist of SAP application instances, running on database (DB), hosted on operating system (OS), provisioned on hardware. Change in any one or more of these underlying components (DB, OS or hardware) warrant us to perform migration. Types of migration: Broadly, there are two types

Let's Talk SAP

Search This Blog