Apart from providing software services, SAP HANA benefits its customer from hardware standpoint. If you’re a HANA customer you can choose the vendor, the storage types and the networking that suits your requirements. Some common vendors are Inspur, Unisys, Dell etc. Before migrating the code to production environment, the environment that is accessed by the end users of an application, you can test the code in non-production environment and hence build the systems which are much more cost effective. For production systems there is a fix CPU to RAM ratio.
As the data in a database grows you have to upgrade the system hardware so as to accommodate increasing data volume and workload, so there are two ways through which you can scale the SAP HANA systems: - Scale-up and Scale-out.
What is SCALABILITY?
Capability of any computer hardware/software which can take full advantage of its changed context in terms of adding or reducing resources.
SCALE-UP in SAP HANA: Vertical Scalability
This feature enables you to increase the size of physical machine by adding the amount of resources such as RAM/CPU for processing. If I talk about SoH (Suit on HANA systems e.g., ECC , CRM , SCM etc), they can only be scaled up with a maximum of 12 TB RAM. There is no scale-out option for SoH. But for other business use cases, such as BW on HANA or Datamarts both scale-up and scale-out options are available. The maximum scale-up and scale-out for them is 3TB/node. Supporting vendors include Cisco, Hitachi, HP, IBM, Lenovo, Fujitsu, Huawei, SGI etc.
HP provides 16 sockets and 4TB for analytics, 12 TB for business suite. SGI provides 8 TB for analytics, 24 TB for Business Suite. If we talk about Business Suite systems they fit-in on 8-socket 6TB system. So for business suite scale-up is preferred.
SCALE-OUT in SAP HANA: Horizontal Scalability
This feature will enable you to combine multiple independent nodes/machine into one system. Vendor supporting scale-out appliances are Cisco, Hitachi, HP, Huawei, Lenovo, Dell, Fujitsu etc. Hitachi, HP, Lenovo have 1TB and 2TB scale out appliances. Generally customers buy 5-10 TB HANA production systems. You will always require a good HANA consultant so as to know which type of system to go for as they have the ability to define the partitioning strategy. The biggest SAP Business Suite installations consists of 32-socket 24 TB provided by SGI. So one suggestion, if you need more than 2 TB then go for scale-up but if your requirements exceed 2TB then going for scale-out is far better.
Finally I would end up with expert advice: SAP experts recommend to go for scale-up first before scale-out so that you can manage and configure a single system as compared to a cluster. For analytical processing scale-out option works best but if there is a medley of analytical and transactional processing then scale-out turn out to be challenging.
