The virtualization path less traveled
- 10 September, 2011 06:18
To update an old IT saying about IBM and job security, few IT managers may get fired for choosing VMware to virtualize their infrastructure. VMware, after all, is the safe bet: The company currently enjoys 80 percent of the server-side virtualization market, according to IDC.
But at least one company, Salsa Labs, which offers an online platform for advocacy groups, has adopted a less widely used virtualization platform, one from Red Hat.
Red Hat's Red Hat Enterprise Virtualization (RHEV), based on the KVM hypervisor, proved to be a better fit for the company, said Justin Nemmers, Salsa Labs chief operating officer, in an interview coordinated by Red Hat.
"Both RHEV and VMware had the core features that we needed," Nemmers said, adding that RHEV approach was much more inexpensive. Nemmers did not detail the price differences between the two software packages, other than to note "for us, [the difference] was significant," he said.
Salsa Labs runs a SaaS (software-as-a-service) platform that can be used by advocacy groups to organize their campaigns and get their messages out. Over 2,000 groups, constituting 50 million members, currently use the service. Salsa sends out about 1.34TB of data every month.
The company has experienced 30 to 40 percent year over year growth since its launch in 2004, so virtualization seemed like a logical step to smooth growing pains in the IT department.
Prior to virtualization, the company would set up a new server whenever some new function was needed. This approach was problematic insofar as when the server went down the function would not be available.
By placing the application in a virtual machine (VM), Salsa could move it from a troubled server to one that worked. The company could also save hardware costs by running multiple VMs on a single server.
Salsa relies almost entirely on Linux-based open source software for its operations: The Salsa platform, built on Java, runs on Apache Tomcat. Nginx is used for the Web server software. MySQL databases and a MongoDB data store hold the data. Red Hat Directory Server authenticates users and the software stack is managed through Red Hat Network Satellite.
When it came to choosing virtualization infrastructure, the decision came down to VMware or Red Hat. Choosing Microsoft was "never even an option," given that Salsa's IT talent was more familiar with Linux, Nemmers said. With those two companies, "the decision, realistically, was around cost as much as minimum functionality that we needed."
Live migration was one required feature. To move a VM from one physical server to another while keeping it running was critical for Salsa. Both Red Hat and VMware offered this capability, though VMware's came with "considerable additional cost," Nemmers said.
Additional costs also stemmed from the fact that Salsa would have to purchase additional OS licenses if it wanted to run VMware, in addition to the cost of obtaining the VMware software itself (VMware did not immediately respond to a request for comment). Because KVM is built into the Linux kernel itself, Salsa could manage virtual infrastructure with its existing RHEL servers. All it needed was a management console, which RHEV provided.
Another benefit with RHEL: Nemmers knew that an upcoming version of KVM would provide the ability to adjust the amount of memory and the number of CPUs each VM would use. This feature could be valuable for Salsa, given that the clients' workloads can vary greatly.
Today, operations of the Washington D.C.-based Salsa Labs is 70 percent virtualized, running 180 VMs across 50 Hewlett-Packard C-Class blade servers. Only a few very large databases are not virtualized, because they would require additional investment in storage.
"As I end-of-life older hardware, anything running on the middle tier will be virtualized," Nemmers said.
To virtualize the infrastructure, Salsa created a handful of templates based on different functions, such as a Web server template and a database template. Templates can be quickly deployed whenever the functionality is required. In effect, they replace the need for new hardware.
"In situations where we'd normally needed to increase the actual hardware allocation, we'd just virtualize [the function] instead," Nemmers said.
Red Hat got a late start to virtualization game, releasing RHEV in 2009 -- years after VMware and even Microsoft carved out their spots in the market. Whether the company can build its own base of users remains to be seen. Nemmers is not worried about choosing a virtualization package that could very well never be a dominant platform in the field, however.
"KVM has enough of a foothold in the industry. Even if Red Hat de-supported RHEV, I would have no concerns about continuity of operations," Nemmers said. "We could export those virtual guests into our own KVM cluster and be up and running in no time."