Leveraging Zero Downtime Option of SUM for SAP S/4HANA release upgrades and updates
In this blog I describe how you can leverage Zero Downtime for applying support package stacks in SAP S/4HANA.
Abstract: With SUM 2.0 SP04, a new pilot program will be available to run zero-downtime updates for SAP S/4HANA. This blog describes the availability and also the boundary conditions of the Zero Downtime Option.
Update (June 28, 2019): Update path for SAP S/4HANA 1809 added
Update (June 29, 2020): Upgrade and update paths adjusted as per SAP Note 2707731
Update (January 15, 2021): Upgrade path to SAP S/4HANA 2020 added
In the past years, the approaches to minimize downtimes evolved significantly. When talking about the approaches shipped along with Software Update Manager 2.0 there are three different main approaches available for applying support packages in SAP S/4HANA:
Both, the standard approach, as well as the near-Zero Downtime Maintenance (nZDM) contain major improvements for minimizing the technical downtime. These approaches are generally available for all customers.
However, neither standard, nor near-Zero Downtime Maintenance offer the option to reduce the technical outage down to zero. This can be achieved by the next level of downtime-optimization: Zero Downtime Option of SUM. One important thing to be considered as well: the more you want to optimize the downtime, the more effort you have in the project. The effort includes project planning effort, as well as testing effort which is higher in case of zero-downtime updates.
There are three facts about the Zero Downtime Option:
- The Zero Downtime Option comes along with the standard tool for software maintenance: Software Update Manager. There’s no additional license needed and of course no separate tool required.
- The database footprint is rather small since not the entire database will be cloned. Instead, only selective tables will be cloned. The clone tables are determined based on the changes to be performed with the maintenance event.
- The technical downtime goes down to a single restart of the application servers. The database will not be restarted. Usually, the restarted might take approx. 5 to 15 minutes dependent on the number of application servers.
How does ZDO work?
Let’s compare the three approaches: standard, nZDM, and ZDO:
As you can see on the picture above, the technical downtime already shrinks when using the nZDM approach which is generally available. However, only with ZDO, the technical downtime can be eliminated and replaced by the so-called uptime on bridge. You’ve never heard of the bridge? Don’t panic!
The terminology bridge has been introduced with ZDO. It’s a part of the existing system that runs in parallel to the upgrade instance where the maintenance event is triggered by the Software Update Manager. Usually, at a certain point of time, end-users will be logged-off from the system and the technical downtime starts. In case of ZDO, all users will be transferred to the so-called bridge sub-system. The good thing: the users don’t even realize this since the transition to bridge happens in the background.
What happens during the transition? In simple words, it’s just reconnecting from one database schema to another one. If you’re interested in more technical insights, I’d like to promote the recordings of my TechEd sessions 2018, 2019, and 2020 as referenced below in section “Further Information”.
The Zero Downtime Option of SUM for SAP S/4HANA is available for the following SAP S/4HANA releases:
- SAP S/4HANA 1809 FPS 01 or higher
- SAP S/4HANA 1909 SPS 00 or higher
- SAP S/4HANA 2020 SPS 00 or higher
Upgrading to a higher major release is available as per description in the official SAP Note 2707731:
- SAP S/4HANA 1809 FPS 01 or higher to SAP S/4HANA 1909 FPS 01 or higher
- SAP S/4HANA 1909 SPS 00 or higher to SAP S/4HANA 2020 SPS 00 or higher
Zero Downtime Option of SUM for SAP S/4HANA is currently available for service-based pilot projects only. So, it’ refers to a restricted shipment which makes it mandatory that someone from SAP (e.g. Premium Engagement or SAP Consulting) is involved into the pilot project.
If you’re interested in being a pilot customer, follow the instructions described in SAP Note 2707731 “Prerequisites and restrictions of Zero Downtime Option of SUM for SAP S/4HANA”. This SAP Note contains all prerequisites about the supported source and target versions, as well as the information about the registration process for the pilot program.
- Replay of SAP TechEd 2020: DT111 – Discover Zero Downtime Maintenance for Upgrading SAP S/4HANA
- Replay of SAP TechEd 2019: CAA301 – Leveraging Zero-Downtime Maintenance for SAP S/4HANA
- Replay of SAP TechEd 2018: CNA306 – Get Your SAP S/4HANA Ready for Running a Zero-Downtime Update Project
- SAP Note 2707731 – Prerequisites and restrictions of Zero Downtime Option of SUM for SAP S/4HANA
- Blog: Impact Analysis of Software Update Manager
- SAP Note 2471883 – SUM Impact Analysis for ZDO
- Roadmap Viewer SAP S/4HANA Upgrade and Product Integration Roadmap
- Blogs from Parishudh Reddy Marupurolu about ZDO project planning and Silent Data Migration
Product Management SAP SE, Software Logistics