Downtimes implode

It is easy to imagine what it means when SAP systems do not or no longer run as they should: Business comes to a standstill and business processes are interrupted because transactions cannot be carried out; in the worst case, production cannot be carried out for hours, resulting in lost sales, perhaps even in connection with recourse claims; or: employees are virtually condemned to twiddle their thumbs because they cannot work with "their" SAP system as usual.

Many unfortunate circumstances can be cited when mission-critical SAP systems are no longer available. Of course, not only production companies can be affected, but all SAP user companies from very different industries.

The topics of high availability and disaster + recovery have been on the SAP topic agenda for decades in mission-critical SAP deployments as part of what is known as data center readiness.

For SAP, but also for partners such as SUSE. Products, solutions and concepts for this are in fact subject to a continuous improvement or optimization process.

The goal here is to support a kind of non-stop IT that, if possible, comes very, very close to the goal of having zero downtime - "near-zero downtime."

Ensemble of features and products for HA and D+R

When it comes to data center readiness, the main focus is always on the SAP infrastructure complex. As is well known, this has changed with the in-memory database SAP HANA and HANA-based SAP applications such as SAP S/4HANA, C/4HANA or BW/4HANA.

Not only on the server side, but also in terms of the operating system platform used. SAP specified the Linux open source operating system for HANA. Just as SAP has increasingly relied on open source solutions since/with HANAization and cloudization.

Business- or mission-critical designed infrastructure open source and Linux solutions effectively underpin the plan of a mentioned non-stop IT or the goal "Toward or Near-Zero Downtime" and thus an increased SAP availability. And this in relation to unplanned and planned downtimes.

Working with SAP and service partners, SUSE provides a coordinated ensemble of automated high-availability (HA) and disaster recovery (DR) solutions for both on-premise and cloud operations that have proven to benefit SAP customers worldwide.

One is the recommended and market-leading HANA Linux operating system, SUSE Linux Enterprise Server for SAP Applications, with the SUSE Linux Enterprise High-Availability Extension (HAE) add-on (for physical and virtual servers) as part of the product. This can help eliminate single-point-of-failures and provide automated service failover, such as of a HANA cluster.

Second, SUSE provides the so-called live patching technology as an option in SLES for SAP Applications, which enables kernel fixes quasi on the fly - without rebooting the HANA Linux system and without stopping SAP applications in use.

And third, SUSE offers powerful management software for the underlying Linux of SAP applications in the form of SUSE Manager.

SAP HANA cluster architecture from SUSE

SLES for SAP Applications is a special or optimized version of SUSE Linux Enterprise Server for all SAP Netweaver and HANA-based solutions and is being continuously developed.

This is a package set of operating system and services for mission-critical server operation on demand with minimized installation and administration effort.

For example, the included Installation Wizard ensures a high level of automation when deploying both SAP applications and the Linux infrastructure (including third-party applications). Or: Special functions support SAP application performance.

As already mentioned, SLES for SAP includes the High Availability Extension (HAE). This provides a high-availability Linux solution that has also received the "SAP Netweaver High Availability Cluster 730 certification".

In addition, physical AND virtual environments (heterogeneous clusters) are supported to a far-reaching practical extent. In the case of SUSE HAE, for example, SUSE has developed a fully automated process with VMware that monitors and controls all processes. Here, SUSE Linux HAE takes over the monitoring of the SAP applications and VMware HA the monitoring of the virtual machines.

Some virtualization platforms offer live migration, which makes it possible to move virtual machines from one physical host to another at runtime.

This eliminates even the short downtime that occurs with redundant servers in a redundant design in the event of a hardware failure, and before the other server starts its activities. Also, with the HAE cluster solution, complete separation of the virtual and physical layers is possible at runtime.

With the SUSE HAE solution, SAP workloads are fundamentally better protected against possible hardware failure. All components of the cluster solution communicate with each other and the smooth running of all processes is ensured across all providers.

In addition, the SUSE HAE solution ensures automated SAP HANA failover for SAP HANA system replications.

As the market penetration of SUSE SLES for SAP Applications in HANA and HANA-based SAP applications continues to grow, HAE installation numbers have also increased significantly.

In other words, when SLES for SAP is used, the SUSE HA Extension also usually comes into play as a cluster solution, which, by the way, is based on the open source solution called "Pacemaker".

SUSE was quick to adapt or further develop the open source cluster solution for mission-critical SAP use. In this context, the so-called SAP HA best practices provided by SUSE deserve special mention.

They describe in detail both the installation of the SUSE cluster solution for various SAP scenarios and its administration during operation. Both SUSE Services partners and customers are increasingly using this beneficial and free guide.

Live patching of the Linux kernel

SAP customers or SAP end users require more and more - in terms of high availability, in terms of unplanned and planned downtimes, and thus inevitably also in terms of service level agreements (SLAs).

After all, SLAs are simply the hard criteria by which IT and SAP operations managers are measured. This is also because there are hardly any companies left in which there are no SLA agreements between IT and business departments. It is often contractually agreed what the SLAs actually look like, when and how SAP is available or not.

The wish, and often also the expectation, from the business department to the business top management is nowadays no more and no less: SAP services should be available as always as possible; the expectation regarding a 7x24x365 availability of SAP is more or less simply existent.

Of course, IT or SAP operations in companies strive to do what is feasible. But they depend on optimization aids or technology innovations from the IT industry to get very, very close to 100 percent availability.

As a pioneer in enterprise Linux deployment, SUSE has always aimed to continuously drive forward what has been achieved in this regard, and provides live patching, a technology that enables critical patches to be applied to the SUSE kernel on the fly.

And it does so without requiring a system reboot and the need to account for planned downtime. In other words, this allows on-going instead of stop-and-go to perform an update of the Linux kernel.

As a consequence, this has a positive effect on planned downtimes and SLAs for mission-critical SAP use. But also in the need to implement unplanned critical Linux kernel patches without having to shut down and reboot numerous servers.

Advantages of SAP HANA deployment

Live Patching is based on various Linux technologies. Originally, Live Patching was a research project of SUSE Labs. However, it quickly became apparent that it could significantly optimize business-critical SAP deployment, for example. By using existing Linux technologies, Live Patching requires only a small amount of code and administration.

What's more, HANA deployment eliminates the need for system reboots and thus in-memory load times, which normally take a certain amount of time. For technical HANA system management, SUSE provides SUSE Manager. It is a product that offers distinct Linux system management functionality.

One focus is Linux server updates, even for large installations. SUSE Manager includes methods, procedures and software functionality to efficiently install, manage and control Linux systems.

Another focus of SUSE Manager is system monitoring and the provision of information about the version/patch status of an IT landscape.

On the one hand, SUSE Manager significantly reduces the complexity of SAP environments because all components and elements of an SAP server infrastructure can be administered and managed from only one central location and on the basis of a sophisticated user interface.

On the other hand, it can be used to manage individual environments required for enterprise operations (for development, test, integration and production systems, for example) with pinpoint accuracy.

Furthermore, SUSE Manager can be used to simplify the implementation of compliance requirements or to realize compliance and proof of compliance. In addition, SUSE Manager stands for achieving cost benefits, in particular through the fact that manual and recurring work is automated.

Of course, SUSE Manager can automatically inventory the operating system platform with hardware and software information.

Software patch statuses are also recorded. And: Configuration changes are detected automatically. Likewise, configurations can be changed or reset to a defined state in the past via SUSE Manager. SUSE Manager and SUSE Linux Enterprise Server (SLES) for SAP Applications are closely aligned.

At the outset, it says that SUSE, in cooperation with SAP and service partners, provides a coordinated ensemble of automated high-availability (HA) and disaster recovery (DR) solutions for both on-premise and cloud operations that have proven to benefit SAP customers worldwide and continue to evolve.

For example, the innovative collaboration between SAP, Intel and SUSE marked a new milestone with the use of Intel Optane/Persistant Memory in HANA deployment together with SUSE Linux in data centers.

The technology is based on NVDIMM technology, which, in simple terms, makes it possible to move large amounts of data permanently and even persistently closer to the processor. At the same time, latency times are minimized when fetching data from the main memory.

NVDIMM stands for Non-Volatile Inline Memory Module; for a main memory in which contents do not volatilize even in a powerless state. SAP HANA as an in-memory database and SAP HANA-based applications such as S/4 derive particular benefits from this.

You could say: Persistent Memory is made for HANA. SAP itself considers the possibility of providing Persistent Memory for HANA to be nothing more, but also nothing less than a "milestone".

SAP Open Source Companion

SUSE was the first Linux distributor and SAP open source companion to fully support Intel Optane DC Persistent Memory in conjunction with HANA with its SLES for SAP Applications operating system platform.

Whereby the abbreviation DC means Data Center and thus Persistent Memory is designed for use in data centers. This once again underscores the close and deep partnering between SAP, Intel and SUSE in mission-critical SAP deployments.

For SAP customers, persistent memory technology enables new or optimized applications for data access and data storage compared to traditional technology (using SSDs). In the end, this means nothing other than that the business can derive even more monetary benefits from the use of HANA.

One aspect, for example, is the use of cost-effective in-memory database solutions with large data volumes. Another is the flexible definition of "warm" and "hot" data. For example, in SAP Analytics or SAP Big Data applications.

Furthermore, Persistent Memory allows to significantly shorten in-memory load times or to minimize recovery times - and thus to shorten possible DR times as well as Toward Zero Downtime.

In SAP/Intel tests, for example, the startup/load time for a six TB SAP HANA database with persistent memory was drastically reduced compared to a traditional system (with SSD). Namely, from 50 minutes to four minutes.

Trusted Advisor in the SAP Community

SUSE and SAP have been working closely and successfully together for over 20 years and maintain a "Worldclass Partnership". SUSE also maintains a number of partnerships with SAP partners.

Today, SUSE is the preferred solution provider and partner in the SAP community for several thousand companies around the globe and in virtually every industry that use SAP technologies and solutions.

What's more, SUSE is considered the trusted advisor and "safe bet" when it comes to SAP deployment. It is estimated that between 80 and 90 percent of all HANA installations use SUSE Linux Enterprise Server (SLES) for SAP Applications, both on-premise and via public cloud providers-partly because SUSE provides numerous SAP- and SAP-HANA-specific features (SLES for SAP is currently available in version 15.1).

Of course, this includes all HANA-based SAP solutions, such as S/4HANA, BW/4HANA, C/4HANA or SAP Data Intelligence. In addition to SLES for SAP Applications, SUSE also provides other products such as the CaaS Platform (container management/Kubernetes implementation from SUSE), SUSE Enterprise Storage (Ceph) as a storage solution or SUSE Manager (for enterprise system management) to increase the degree of automation in Linux operations.

SUSE's trusted advisor position in the global SAP community is also underpinned by the fact that at the annual SAP Innovation Awards (formerly SAP HANA Innovation Awards), SUSE is recognized as a partner that has innovated with SAP platform technologies to deliver business transformation in a special way and with a special digitalization implementation.