Over the past few months, businesses across every industry have faced unexpected challenges in keeping their enterprise IT systems safe, secure, and available to users. Many have experienced sudden spikes or drops in demand for their products and services, and even more have shifted almost overnight to a home-based workforce. Even enterprises that experienced the stress of these changes and came through with flying colors may be wondering whether their current approach to protecting the availability of these applications is as robust as it needs to be.This question can be especially urgent for companies that run their SAP enterprise applications in on-premises environments. These organizations are often already struggling with running business-critical SAP instances on-premises because they can be complex and costly to maintain. But they see the on-prem option—backed up with major investments in high-availability (HA) systems and infrastructure—as the best way to ensure the security and availability of these essential applications. They know just how much their users depend on these systems and how disruptive it can be to deal with unplanned outages. However, IT organizations charged with running on-premises SAP landscapes, in many cases, must also manage a growing number of other business-critical applications—all while under pressure to do more with less.For many organizations, this is an unsustainable approach. In fact, according to a 2018 survey looking at trends in HA solutions, companies at the time were already struggling to hold the line with on-premises application availability:95% of the companies surveyed reported at least occasional failures in the HA services that support their applications.98% reported regular or occasional application performance issues.When HA application issues occured, companies surveyed spent 3–5 hours, on average, to identify and fix the problem.Things aren’t getting easier for these companies. Today’s IT landscape is dominated by risk, uncertainty, and the prospect of belt-tightening down the road. At the same time, it’s especially important now to keep your SAP applications—the software at the heart of your business—secure, productive, and available at all times.At Google Cloud, we’ve put a lot of thought into solving the challenges around high-availability for SAP environments. We recognized this as a potential make-or-break issue for customers. And we prioritized giving them a solution: a reliable, scalable, and cost-effective SAP environment, built on a cloud platform designed to deliver high-availability and performance.3 levels that define the SAP availability landscapeUnderstanding how to give SAP customers the best possible high-availability solution starts with recognizing that “availability” means different things to different customers, depending on their business needs, budgets, SAP application use cases, and other factors. That’s why we look at the SAP high availability (HA) landscape in terms of three levels, each with its own costs, benefits, and trade-offs to consider within an overall availability strategy.Level 1: InfrastructureFor some customers, simply moving an SAP system from on-premises hardware to Google Cloud infrastructure can deliver big improvements in uptime. Google Cloud has two built-in capabilities that are especially important to achieving this goal and together can reduce or even eliminate downtime due to hardware failures:Live Migration. When a customer’s VM instances are running on a host system that needs scheduled maintenance, Google Live Migration moves the VM instance from one host to another, without triggering a restart or disrupting the application. This is a built-in feature that every Google Cloud user gets at no additional cost. It works seamlessly and automatically, no matter how large or complex a user’s workloads happen to be. Google Cloud conducts hardware maintenance, applies security patches and updates, globally, without telling a single customer to restart their VM, all with the power of Live Migration. Host auto restart. When an unplanned shutdown affects a user’s VM instances, this feature swings into action, automatically restarting the VM instance on a different host. When necessary, it calls up a user-defined startup script to ensure that the application running on top of the VM restarts at the same time. The goal is to ensure the fastest possible recovery from an unplanned shutdown, while keeping the process as simple and reliable as possible for users. Level 2: DatabaseEvery SAP environment depends on a central database system to store and manage business-critical data. Any SAP high-availability solution must consider how to maintain the availability and integrity of this database layer. In addition, SAP systems support a variety of database systems—many of which employ different mechanisms to achieve high-availability performance. By supporting and documenting the use of HA architectures for SAP HANA, IBM Db2, MaxDB, SAP ASE, and Microsoft SQL Server, Google Cloud gives customers the freedom to decide how to balance the costs and benefits of HA database systems for their SAP environments.Level 3: Application serverSAP’s NetWeaver architecture helps users avoid app-server bottlenecks that can threaten HA uptime requirements. Google Cloud takes that advantage and runs with it by giving customers the high-availability compute and networking capabilities they need to protect against the loss of data through syncronizationand to get the most reliability and performance from NetWeaver.5 ways Google Cloud supports high-availability SAP systemsThere are many other ways Google Cloud can help maximize SAP application uptime, even in the most challenging circumstances. Consider a few examples, and keep in mind how tough it can be for enterprises, even larger ones, to implement similar capabilities at an affordable cost:1. Geographic distribution and redundancy. Google Cloud’s global footprint currently includes 22 regions, divided into 67 zones and over 130 points of presence. By distributing key Google Cloud services across multiple zones in a region, most SAP users can achieve their availability goals without sacrificing performance or affordability. For example:Compute Engine instance groups can be distributed and managed across the available zones in a region.Compute Engineregional persistent disks are synchronously replicated across zones in a region.2. Powerful and versatile load-balancing capabilities. For many enterprises, load balancing and distribution is another key to maintaining the availability of their SAP applications. Google Cloud meets this need with a range ofload-balancing options, including global load balancing that can direct traffic to a healthy region closest to users. Google Cloud Load Balancing reacts instantaneously to changes in users, traffic, network, backend health, and other related conditions. And, as a software-defined service, it avoids the scalability and management issues many enterprises encounter with physical load-balancing infrastructure.3. Tools that keep developers focused and productive. Google Cloud’sserverless platform includes managed compute and database products that offer built-in redundancy and load balancing. It allows a company’s SAP development teams to deploy code without worrying about the underlying infrastructure. Google Cloud alsosupports CI/CD through native tools and integrations with popular open source technologies, giving modern DevOps organizations the tools they need to deliver software faster and more securely.4. Flexible, full-stack monitoring. Google Cloud Monitoring gives enterprises deep visibility into the performance, uptime, and overall health of their SAP environments. It collects metrics, events, and metadata from Google Cloud, Amazon Web Services, hosted uptime probes, application instrumentation, and even application components such as Cassandra, Nginx, Apache Web Server, Elasticsearch, and many others. Cloud Monitoring uses this data to power flexible dashboards and rich visualization tools, which helps SAP teams identify and fix emerging issues before they affect your business.5. Making the most of an SAP system’s inherent HA capabilities. Every SAP instance already includes some very powerful HA technologies, and one of our most important jobs is to ensure that Google Cloud fully supports these built-in capabilities. Let’s look at two examples of how we do this:At the database level, Synchronous SAP HANA System Replication (HSR) is one of the most important application-native technologies for ensuring HA for any SAP HANA system. It works by replicating data continuously from a primary system to a secondary system, and it can be preloaded into memory to allow for a rapid failover if there’s a disaster.Google Cloud supports and complements HSR by allowing the use of synchronous replication for SAP instances that reside in any zone within the same region. That means users can place their primary and secondary instances in different zones, keeping them geographically separated and protected against failure on an entire zone.At the application level, the SAP architecture allows the use of multiple NetWeaver app server instances to maintain high-availability performance. Yet there’s still a single point of failure to contend with: the SAP NetWeaver global file system, which must be available to all SAP NetWeaver instances in a HA system.Google Cloud offers two ways to address this issue. The first uses a high-availability shared storage solution, such as NetApp Cloud Volumes. The second uses Google Cloud’s support of replicated zonal persistent disks to replicate the SAP global file system between the nodes in an HA cluster. Both of these approaches ensure that a file system failure won’t put a business’s high-availability SAP environments at risk.Explore your HA optionsWe’ve only scratched the surface when it comes to understanding the many ways Google Cloud supports and extends HA for SAP instances. For an even deeper dive, our white paper, “SAP on Google Cloud: High Availability”goes into more technical detail on how you can set up a high-availability architecture for SAP landscapes using Google Cloud services.
Quelle: Google Cloud Platform
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