Business Challenge Faced
Capita Group Systems (CGS) CIO engaged with Aliter Consulting in Q2 of 2014 to architect, design, manage and execute their move from aging hardware running SAP on Oracle/AIX to newer hardware that could meet the projected growth in their user base plus the following key requirements:
Over the months leading up to our engagement with CGS there had been a number of occurrences where the existing platform had failed to deliver in some of these areas all of which had to be addressed by the new infrastructure. The existing platform was also incapable of supporting the current user base and retain an acceptable level of performance. A significant increase in the user base was just not possible.
With these requirements in mind, we held extensive discussions with CGS and VCE with a view to adopting their vBlock offering – which was already deployed by Capita IT Enterprise Services (ITES) for their on-premise cloud offering, Capita Private Cloud (CPC). The vBlock technology provides an appliance-like solution where Cisco servers, EMC VMAX storage and VMware are deployed together and factory tested before customer delivery.
ITES were also in the process of commissioning two new data centres approximately 90km apart for disaster recovery purposes and so it was decided that the new SAP platform would be hosted on a virtualized cloud-like platform on vBlocks located at the two new data centres running VMware.
ITES offered two operating systems in their CPC – Red Hat Linux and Windows. It was decided that the SAP estate would be hosted on Red Hat Linux with SAP ASE as the database; the choice of database was driven by commercials; the choice of operating system for a number of reasons – familiarity, security, flexibility and resilience.
For protecting the SAP single points of failure (SPOF) – message and enqueue servers – Red Hat clusters would be deployed. Redundancy in the application would be achieved by deploying at least two application servers (instances) per SAP system hosted on separate virtual machines (VM) protected by VMware HA. Anti-affinity rules in VMware would prevent application instances and clustered services being hosted on the same physical servers.
The VMs hosting the ASE database instances would be protected by VMware HA and SAP Replication Server (SRS), which would also provide disaster recovery for the transactional systems. Symmetrix Remote Data Facility (SRDF) would provide disaster recovery for non-transactional systems such as SAP Enterprise Portal.
The deployment of two vBlocks into two widely spread data centres inter-connected by a fast network link, provided an ideal platform for the disaster recovery solution. All VMs hosting an SAP instance incorporated Site Recovery Manager (SRM) and could be located at either data centre, retaining their host name and IP address. This made the invocation of disaster recovery easy. SRDF replication would ensure the non-transactional data was replicated and SRS would ensure the transactional data was replicated.
For file sharing, a Network Attached Storage (NAS) system was deployed and incorporated into the disaster recovery model with SRDF.
The deployment of vBlock technology brought with it the necessary scalability required – both vertical and horizontal.
The move to ASE had commercial benefits because CGS was able to negotiate a very good deal with SAP for dropping Oracle from their technical bill of materials (BOM). As ASE displays many similar traits to MSSQL, the skills transfer within the existing Basis team was reasonably quick.
The migration to ASE brought with it an increase in the compression compared to Oracle. The ECC database was reduced in size from 4TB to 2TB. This was helped with some aggressive data cleanup in the Basis tables prior to the migration.
Aliter Consulting provided three certified SAP technical consultants to the project for the delivery phase who provided knowledge transfer as the project approached go-live.