The latest release of SAP HANA has brought the concepts of multi-temperature data and lifecycle management to a new level. With SP09, SAP has addressed the size and cost constraints which may prohibit an all in memory solution. SAP HANA with the Dynamic Tiering (DT) option enables placement of the highest value “hot data” in the classic SAP HANA in-memory tables, and less frequently accessed “Warm Data” is placed or migrated to tables which reside on an SAP HANA Extended Storage Host (ES Host).
The data associated with the ES Host will reside on disk and not in-memory, however since data is stored using the same columnar paradigm as classic SAP HANA, performance is optimized for data processing.
SAP Business Warehouse Powered by HANA
The Dynamic Tiering option is Plug & Play for SAP Business Warehouse (BW) 7.4 SP8 Power By HANA. SAP BW provides full access to your data whether it resides in-memory data or on the extended host, access is transparent to the user, so no need to direct your queries to the SAP in-memory store or extended host store.
With the SAP HANA SP09 release BW Objects which can reside on the Extended Storage Host are the Write-Optimized Data Storage Objects and the Persistent Staging Area. Since these objects can comprise between 15% to 40% of the total database footprint, customers using DT in their landscapes can realize substantial savings by reducing the amount of RAM necessary to run SAP HANA. In addition the SAP HANA Extended Storage Hosts can be deployed on either Certified Servers or standard x86 commodity servers.
SAP HANA Native Use Cases
The number of software ISVs and developers choosing SAP HANA as their native database is quite impressive. Whether SAP HANA is being used for Data Marts, Enterprise Data Warehouses, or for custom applications, Dynamic Tiering presents interesting opportunities to make these use cases more robust. It’s important to adhere to the SAP HANA Node to ES Host ratios when using HANA as the native database. When the HANA in-memory database is 64GB to 512GB in size, the Extended Storage Host resident data can be 4 times the size of the HANA in-memory database. Below is a sizing summary:
SAP HANA In-Memory Data
Extended Storage Host Data Ratio
64GB – 512 GB
>512 GB to <2TB
Deploying SAP HANA In The VMware Software-Defined Datacenter
SAP HANA Extended Storage Host is fully supported by SAP to runs on VMware vSphere. It’s interesting to note that SAP does not allow the deployment of a SAP HANA Worker Node and the Extended Storage option on the same physical server. In addition when deploying SAP HANA with DT in the physical world, SAP provides the following guidance:
“The distance between HANA hosts and Extended Storage hosts should be as short as possible to avoid performance impact on distributed INSERTs, UPDATEs, or Queries. Ideally, ES hosts should be placed inside the same rack as the HANA hosts.”
VMware can actually go one better. In the VMware Software Defined Datacenter both the SAP HANA Worker Node virtual machine and the Extended Storage Host virtual machine can be consolidated on a single physical vSphere Host which is a supported SAP configuration. This avoids the performance impact on distributed INSERTs, UPDATEs, or Queries which SAP mentions in the physical world. This is a clear benefit, by consolidating these virtual machines customers can better utilize server resources and increase their ROI. Also the consolidation and co-location of SAP HANA Nodes onto a single vSphere Host may reduce the internode communication latency associated with multi host deployments in a physical SAP Dynamic Tiering landscape.
SAP HANA Dynamic Tiering with VMware HA and Workload Management
For customers who choose to use the Dynamic Tiering option, SAP HANA System Replication is not available in SP09. However as with SAP HANA single node scale up deployments, the Extended Storage Host can be protected against hardware and or OS outages with VMware High Availability (HA). Enabling VMware HA allows the ES Host to be restarted on any vSphere hosts within the vSphere cluster without the need for a dedicated standby server. Also vMotion can be used to perform workload management or zero downtime maintenance by live migrating the ES Host to another server. Since the ES Host can run on both certified and standard x86 hardware, Distributed Resource Scheduler (DRS) can be set to atomically migrate virtual machines to other vSphere hosts within the cluster in order to maximize performance and availability.
SAP has devised a brilliant multi-temperature strategy to manage the data lifecycle of their customer’s SAP HANA landscapes. When deploying SAP HANA with Dynamic Tiering our joint customers can extend and virtualize their SAP HANA databases beyond the 1TB vSphere 5.5 monster VM limitation. I will be discussing these topics in-depth, as well as techniques to simplify and accelerate SAP HANA deployments in the VMware Software Defined Data Center at VMware Partner Exchange 2015 in my session entitled; “Leveraging SAP HANA Dynamic Tiering Strategy and Concepts in The VMware Software Defined Data Center”