Tier-1 database application owners have long argued against putting their performance-sensitive applications in a private or public cloud offering. Server and network virtualization and dynamic workload balancers make it relatively straightforward to provide compute and network quality-of-service (QOS) guarantees within a multi-tenant infrastructure.
But, says Matt Wallace, Director of Cloud Infrastructure at ViaWest, who was a guest in Wikibonâ€™s December 18 Peer Incite, cloud-services providers using traditional storage offerings can only meet the QOS IOPS requirements through dedicated storage systems or massive over-provisioning of networked storage. Both of these approaches are expensive, offer no leverage, and fail to provide some of the core requirements to be considered a true cloud offering:
- Self service,
- On-demand provisioning, and,
- Pay as you go.
Tier-1 applications in public cloud services are particularly challenging, because the application owner has no control of and no visibility into neighbors that might impact storage IOPS performance. Without performance guarantees on an application-by-application basis, noisy neighbors can disrupt application performance. Even when providers offer a guaranteed percentage of available IOPS, this approach only ensures that everyone in the cloud suffers equally from a noisy neighbor.
ViaWest, one of the largest privately-held data center hosting providers in the U.S., has gotten around this challenge by leveraging new technology from SolidFire. The SolidFire solution is much more than blazing performance. As Wallace explained, great performance is available from a variety of all-flash storage array suppliers, such as WHIPTAIL and Pure Storage. However, of the solutions evaluated, only SolidFire had the built-in QoS capabilities, which provided true differentiation.
As anyone who has driven knows, if you slow from 70 miles per hour to 40 miles per hour, it will feel as if you are crawling. Service providers need to be mindful of the negative perception of declining performance, even when performance stays within contracted ranges. QOS management needs to include maximum performance along with guaranteed minimum performance. Without these limitations on available IOPS, applications will do their best to consume all available resources, providing great initial performance that declines as new applications come into the neighborhood or as applications spike.
Action Item: The absence of IOPS QOS management was a major impediment to running Tier-1 apps in the cloud. Because the technology is new, ViaWest performed extensive testing on SolidFire. The early results and feedback from this demanding customer, especially given its embedded QOS management capabilities, argues for serious consideration from anyone running a shared infrastructure, whether public or private cloud.