First published on MSDN on Aug 10, 2017
Protect SAP Applications
Most large and medium sized SAP solutions have some form of Disaster Recovery solution. The importance of robust and testable Disaster Recovery solutions has increased as more core business processes are moved to applications such as SAP. Azure Site Recovery has been tested and integrated with SAP applications and exceeds the capabilities of most on-premises Disaster Recovery solutions and does so at a lower TCO than competing solutions.
Benefits of Azure Site Recovery for SAP Customers:
Azure Site Recovery substantially lowers the cost of DR solutions. Site Recovery does not start Azure VMs until an actual or test failover therefore compute charges are not incurred normally. Only the Storage cost is charged while a VM is in replication mode.
Azure Site Recovery allows customers to perform non-disruptive DR Tests at any time without the need to roll back the DR solution after the test. Site Recovery Test Failovers mimic actual failover conditions and can be isolated to a separate test network. Test failovers can also be run for as long as required.
The resiliency and redundancy built into Azure far exceeds what most customers and hosting providers are able to provide in their own datacenters.
Site Recovery "Recovery Plans" allow customers to orchestrate sequenced DR failover / failback procedures or runbooks, giving you the ability to achieve true Application level DR.
Azure Site Recovery is a heterogeneous solution and works with Windows and Linux VMs, supports VMware and Hyper-V and works well with a range of database solutions.
Azure Site Recovery has been tested with many SAP NetWeaver and non-NetWeaver applications.
The following scenarios:
SAP systems running in one Azure datacenter replicating to another Azure datacenter (Azure-to-Azure DR), as architected
SAP systems running on VMWare (or Physical) servers on-premises replicating to a DR site in an Azure datacenter (VMware-to-Azure DR), which requires some additional components as architected
SAP systems running on Hyper-V on-premises replicating to a DR site in an Azure datacenter (Hyper-V-to-Azure DR), which requires some additional components as architected
3-Tier SAP Systems are recommended for Azure Site Recovery with the following considerations:
Strictly 3-tier systems with no critical SAP software installed on the DBMS server
Replication of the DBMS layer by the native DBMS replication tool (such as SQL Server AlwaysOn).
SAP Application Server layer is replicated by Azure Site Recovery.
ASCS layer can be replicated by Azure Site Recovery in most scenarios.
Non-NetWeaver and non-SAP applications need to be assessed on a case by case basis to determine if they are suitable for replication by Azure Site Recovery or some other mechanism.
Only Azure Resource Manager is supported for SAP systems using Site Recovery for DR purposes.
* Note: SAP Host Monitoring agents are not considered critical and may be installed on a 3-tier DBMS server.
In the diagram below the Azure Site Recovery Azure-to-Azure (ASR A2A) scenario is depicted:
The Primary Datacenter is in Singapore (Azure South-East Asia) and the DR datacenter is Hong Kong (Azure East Asia). In this scenario local High Availability is provided by having two VMs running SQL Server AlwaysOn in Synchronous mode in Singapore
The File Share ASCS is used (this does not require a cluster shared disk solution)
DR protection for the DBMS layer is achieved using Asynchronous replication
This scenario show "symmetrical DR" – a term used to describe a DR solution that is an exact replica of production, therefore the DR SQL Server solution has local High Availability. The use of symmetrical DR is not mandatory and many customers leverage the flexibility of cloud deployments to build a local High Availability Node quickly after a DR event
Customers may also reduce the size of the VM type used in the DR datacenter and increase the VM size after a DR event
The diagram shows that the SAP NetWeaver ASCS and Application server layer is replicated to DR via Azure Site Recovery tools
Note: SAP now supports deploying the ASCS without the requirement to have a shared disk (called SAP ASCS File Share Cluster). Azure Site Recovery also supports SIOS Shared Cluster Disks
Following is a list of useful SAP Notes for various requirements: