Average CPU utilization on virtual infrastructure is at least 60% compared to about 20% before we started virtualizing our data centers.

Our end users have been empowered to do things they were not able to or that were hard to do with physical servers. For example, engineering teams are able to use self-service tools to create their own mini data centers with total control via remote console, remote power control, snapshots, etc.

At Sybase we have utilized all the above technologies to create an infrastructure that is helping our engineering folks to become more efficient and at the same time help Sybase in the greening of the data centers.

Virtualization Technologies Used at Sybase
At Sybase, a heterogeneous environment with different kinds of virtualization technologies is in use. For x86-based workloads, Sybase IT is using products from VMware such as VI3 and Lab Manager to run Linux, Windows, and Solaris x86. Some FreeBSD VMs are also running. For RISC-based workloads, technologies from IBM and Sun are used. IBM virtualization is based on Dynamic Logical Partitions (DLPAR) running on P-Processor servers and hosting AIX and Linux (Power) virtual machines. LDOM and Container technologies from Sun Microsystems are used to run SPARC Solaris virtual machines.

Limitations of Virtualization
Despite all the benefits of virtualization, not all workloads are suited to run on virtual machines. Sybase IT has developed guidelines to assist end users in making the decision to virtualize or use physical servers. Workloads that have very high resource requirements are typically not run on virtual servers as the consolidation ratio is reduced significantly (one or two VMs per physical server) and the benefits are not that attractive anymore. Workloads that are highly sensitive to any overhead such as benchmarks are only run on physical servers.

Use Cases
Use Case: Self-Service QA Environment for PowerBuilder and Mobile Enterprise Engineers
IT was asked to create a few vanilla virtual machines with various operating systems for engineering groups working on PowerBuilder and Mobile Enterprise products. The operating systems consisted of different versions of MS Windows and Linux. The engineers then customized the systems and installed the necessary applications needed for their QA work. IT then created a library of templates and gave descriptions to them that made it clear to end users exactly what the makeup was. At this point engineers were able to check out the templates and create their own mini lab environments. Some engineers needed different variations of the environments and would create a snapshot after they had the desired configuration. This way the engineers were able to check out the exact environment needed for a test. With snapshots they were able to revert back in time with just a few clicks. Teams in Dublin were able to share their environments or test results easily with teams in APO and vice versa.

The engineers had complete control and access to their virtual lab environments. They were able to gain console access, power cycle the virtual machine, create snapshots at will, and add or destroy virtual machines without ever needing help from IT. All this was done without touching any piece of hardware. This level of empowerment and remote management capabilities has never been experienced by many of our engineering groups and is very well received.

Use Case: ASE Cluster Edition
The cluster edition of Sybase ASE required extensive QA work. There was a need for many clusters to be created and had we done this with physical servers only, a lot of hardware would have been needed. It was decided that functional testing could easily be done in the virtual world and we could avoid a significant number of physical server purchases and the time to build them. Not all testing could be done in the virtual world due to some unique test cases requiring physical servers. Several virtual clusters were created where all the ASE nodes were virtual machines and interconnected with virtual connectors and virtual shared storage. In addition to avoiding the purchase of new servers and power/cooling cost savings, this also allowed rapid deployment of new ASE clusters. This greatly helped the QA team to meet their tight schedules and IT was able to assign fewer resources to build and support the physical ASE clusters.

In the physical arena, the ASE cluster needs a physical server for each cluster node (see Figure 6). If the QA team needs to test a 4-node cluster, then four physical servers are required. These servers need shared storage, which is typically a SAN. In addition the servers need network connections for client communications as well as communication between the nodes. The intercommunication requires a separate network connection that is dedicated to this purpose. In addition, the shared storage needs to allow communication to the same set of storage areas (LUNs) by all the ASE cluster nodes. Typical SAN environments allow this but special setup is required.

In order to build this in a virtual environment, we need to be able to create a separate private intercommunication as well as a general public network communication. This is achieved with the use of virtual switches. As for the requirement to allow all ASE cluster nodes to have access to the same storage, the special SAN setting in the physical world needs to be replicated in the virtual storage subsystem. VMWare has support for this shared storage access and we were therefore able to create 2- and 4-node clusters on a single physical box (see Figure 7).

In the case of Solaris-based ASE clusters, we have used the LDOM virtualization from Sun to create virtual ASE clusters. However, due to some restrictions in the use of shared storage, an ASE virtual cluster could not be created on a single physical box. However, we were still able to leverage virtualization as we were able to create several instances of ASE clusters on four physical servers where each virtual cluster spans the physical servers. Figure 8 illustrates the setup for this.

Use Case: Running Sybase Products in Production
Many internal production applications based on Sybase products are running on virtual machines. These were either converted from physical servers using a P2V process or created as part of a new application build. At the time of writing this article we have applications running Sybase products on virtual machines that include EAServer, Afaria, OneBridge, SQL Anywhere, ASE, OpenServer, PowerBuilder, PowerDesigner, and Unwired Accelerator.

Use Case: Using Virtual Appliances for Rapid Deployment of New Applications
Deployment of new applications has become a highly streamlined process as virtual appliances are created and shipped over the WAN to Sybase offices worldwide for a rapid, error-free installation. Virtual appliances can be considered as pre-built virtual machine templates with the necessary application software stack already installed. The OS that makes up the template is optimized for the application it is supposed to run on. Sybase IT now deploys new applications worldwide using virtual appliances that allow IT staff to rapidly deploy these applications with minimal intervention. Sybase IT has also started using the Open Virtualization Format (OVF) standard for virtual appliances. This standard allows virtual machine properties to be captured accurately and gives more flexibility when building and deploying multi-tiered virtual appliances. The format also allows platform independence.

Conclusion
With the virtual infrastructure we have been able to provide an environment that gives high availability at a fraction of the cost of building similar capabilities with physical machines. With snapshot technology, dev/test environments are a true replica of the production environment, and issues due to configuration differences are prevented. Sybase is actively involved in ensuring that its products run on new platforms as they emerge and continues to ensure that virtual environments are used internally to support applications based on Sybase products. Sybase IT continues to push the envelope in using virtualization technologies to provide the maximum efficiency improvements to Sybase Engineering so that they can continue to deliver quality products to our external customers. Virtualization is one of the building blocks of the next big thing across the horizon - Cloud Computing.