XENIUM rescues server virtualization project with Citrix XenServer

Founded in 2002 and based in Wroclaw, Poland, XENIUM is a technology-centric developer and operator of complex web sites, portals, web applications and custom e-commerce solutions. A leading property in the XENIUM portfolio is Dobreprogramy—“good programs.” Dobreprogramy is the largest software and information technology site in Poland, and ranks among the top 10 Polish web sites overall with an audience of nearly six million users generating more than 40 million page views per month. XENIUM also publishes TechIT, a high-end web site for network administrators and systems engineers, and Gamikaze, a site targeted at the gaming and digital entertainment community.

Virtualizing Vyatta – VMware fails to keep up with demand

As an operator of several high-profile, high-traffic web sites, the performance and reliability of its network, systems and applications are top priorities for XENIUM. In its business, leaving users hanging because of inadequate system capacity, network congestion or the failure of any component in the end-to-end path—a situation that drives users away from rather than to sites—is simply unacceptable. XENIUM constantly looks for steps it can take to improve the performance and reliability of its web sites.

Like most organizations today, controlling costs is a major focus for XENIUM. The potential for improved reliability, and significantly reducing infrastructure and operating costs was the driving force behind the initiative by XENIUM to virtualize much of its computing environment.

“We saw server virtualization offering us several benefits,” explained Wojciech Kowasz, chief systems engineer at XENIUM. “Not only did it have the promise of reducing costs and complexity, but with features such as live migration we could also begin to work toward having our sites and services be more dynamic, more resilient—all without the need for operator intervention.”

The server virtualization product originally selected for this initiative was VMware® ESXi™ Single Server (now VMware vSphere Hypervisor) because it was free and because Xenium felt that ESXi had a more reliable track record of supporting Linux® workloads than Microsoft® Hyper-V™. This was a key requirement as XENIUM ran Vyatta, a software-based, open source network operating system, on Linux.

It wasn’t long, however, before XENIUM encountered a significant roadblock. As the XENIUM web sites steadily grew in popularity, the now virtualized instances of its BGP routers were unable to keep up with the greater traffic loads being generated. The latency for user sessions skyrocketed, as did the rate of packets being lost, even under relatively modest loads of 100 to 200 Mbps. Moreover, these issues were not limited to Vyatta. Other virtual machines running on the same host were also being impacted in the same negative manner. After several weeks of failed attempts to remedy the situation, XENIUM decided to move on and evaluate alternative server virtualization solutions. “Although we were in talks with Vyatta engineers and discussed the problems on VMware forums for weeks, we were unable to make the routers work correctly in the ESXi environment,” indicated Kowasz.

Migrating to XenServer – A stable solution with more features

XENIUM decided to test Citrix® XenServer® because it met their leading criteria of having a free edition and being able to support Vyatta on Linux. The results were everything they were looking for, and more.

  • Vyatta performance within the XenServer environment was stable at loads beyond those routinely encountered in production
  • The availability of a preconfigured virtual appliance for Vyatta saved time and effort that would otherwise be needed for installation and integration of associated components
  • Disk reads and access times averaged 10 to 15 percent faster than with ESXi, a seemingly small yet important gain for sites like Dobreprogramy which involve a lot of downloads
  • XenConvert, which automatically converts existing physical servers to virtual machines, worked flawlessly, enabling efficient conversion and automatic importation of Windows Server® 2008 virtual machines originally created for ESXi

Encouraged by these findings, XENIUM migrated from ESXi to XenServer quickly, without any issues and, most importantly, without any impact to ongoing operations. “Because we were migrating from one virtual environment to another, and because of the error-free operation of the XenServer virtual machine conversions tools, we were able to make the switch in a way that had no adverse impact on the quality and availability of our services,” stated Kowasz. It also greatly improved performance for their Vyatta routers.

XENIUM next took advantage of several features not offered by the version of ESXi they had been using (v4.0). “The first smile came when we saw XenCenter. We finally had the ability to manage all of our virtualized servers at once from a centralized, web management console,” noted Kowasz. Administration was further simplified and secured when authentication to its Active Directory domain was enabled.
The benefits kept coming. Because XenServer supports the Microsoft® VHD format for virtual machines—as opposed to the VMDK format required by VMware—administrators can mount related virtual appliances directly on their Windows® 7 notebooks or available Windows Servers®, a convenient ability in maintenance and troubleshooting. The presence of better monitoring and reporting tools than those available with ESXi was also cited as a significant advantage. “Both solutions are available in free flavors, but there is no doubt that Citrix XenServer provides many more features and options,” added Kowasz.

Looking to the future

The overwhelmingly positive experience with XenServer has XENIUM strongly considering how it can use XenServer more extensively. XenServer provides tremendous flexibility in this regard. To obtain functionality beyond that available with the free version, XENIUM can upgrade to a premium option at any time. The Advanced, Enterprise and Platinum editions of XenServer deliver progressively more powerful sets of management, integration, availability and automation capabilities. Features such as Citrix Provisioning Server help to further streamline IT operations and trim associated costs, while high availability, dynamic workload balancing and memory optimization pave the way to even higher levels of system reliability, application performance and overall efficiency. “With a consistent hardware configuration across all of our servers, we should be able to benefit from grouping them in a server pool and taking advantage of the available features to migrate workloads automatically, without the need for manual intervention,” said Kowasz. “Dynamic memory management available with the paid versions of XenServer looks very promising to us.”

About XenServer

XenServer is the leading open source virtualization platform, powered by the Xen Project hypervisor and the XAPI toolstack. It is used in the world's largest clouds and enterprises.
Technical support for XenServer is available from Citrix.