Virtualization combined with cloud processing provides an innovative way of running a SAP HANA installation that can be easily scaled to meet the demands of a company as that company grows. As an enterprise-level software, SAP HANA can scale upwards or scale outwards to have more physical entities available as connection nodes. Both of these may require a company to invest in more hardware in order to deal with the added load. Virtual servers could serve as a temporary (or possibly permanent) solution to this problem of scaling. VMWare provides a robust virtual machine framework that can be used alongside Cloud AWS in order to develop a series of virtual servers on a handful of existing machines. VMWare’s vSphere framework is ideal for the serving of virtual machines with a dedicated purpose. But how does the system perform when put to the test?
In order for us to verify how well SAP HANA performs on virtual machines, we decided that the best method was to actually install the software on a few virtual nodes and see how they performed under stress. We used the VMWare Cloud Foundation (a unified SDCC platform and comes included in the cloud infrastructure provided for use with the cloud platform) to run the system through a series of tests which exercised functionalities of the VMWare Cloud including vMotion, DRS and HA, using those to simulate the day-to-day operations of a large SAP HANA installation on a virtual machine. The size of the virtual machine we used ran 32 vCPU’s and had access to 450 GB of RAM (since this was the closest approximation we could get to the limitations of our physical server which had 32 processing cores and 500GB of RAM). We followed industry best-practice when sizing the hard drives to be used for SAP visitor management system and allocating the memory dedicated to the virtual machine running HANA. In order to ensure that our database was running properly, we ran a series of standard OLAP queries (TPC-DS). During the performance test, vMotion was used to verify that the system could move high-performance applications while in a stress-heavy environment.
Installing SAP S4/HANA wasn’t much different on a virtual system than it was installing to a physical system. After completing the installation, we did verification checks with the OLTP and OLAP tests in order to give us peace of mind that the database installation was both successful as well as functioning properly. The second thing we wanted to focus on in this testing environment was to delve into the viability of using vSphere functionality on a SAP S4/HANA install. We intended to test a case where we would utilize VMware Cloud with a massive-sized SAP S4/HANA install, taking up almost the entire ESX hosting platform, with the expectation that if it could work under these circumstances, it could work in almost any situation.
The first testing simulation involved a reboot that happened without prior warning. Under these circumstances, the VMware HA kicked in, restarting the SAP virtual servers on another of the redundant hosts, ensuring uptime even when the primary system went down unexpectedly. DRS also performed remarkably well, migrating a couple of the smaller VM’s to distributed nodes, thereby providing a more efficient processing environment. The recovery time for the SAP S4/HANA system running on VMware was in the vicinity of a few minutes, proving the effectiveness and viability of vSphere technology alongside the VMware AWS Cluster. The second testing simulation involved simulating the use of vMotion for moving a large virtual machine which was doing processing on our SAP S4/HANA database. We ran this test multiple times and it was confirmed that migration of such a large system under heavy stress was reliable.
While it’s not recommended that a company look into running live versions of their SAP S4/HANA database on virtual machines until the testing with the system is complete and SAP verifies its viability, these tests prove that Dev and Test versions of SAP S4/HANA can indeed function on Cloud AWS. Additionally, it proves that SAP S4/HANA workloads that encompass the entire Physical ESXi host can be run as well as confirming that SAP HANA workloads on the cluster can be used in conjunction with HA and DRS. Finally, we can see from the results that even virtual machines under heavy load can benefit from vMotion reliably, time after time.