VMware vSphere ensures that virtualization overhead is minimized so that it is not noticeable for a wide range of applications including most business critical applications such as database systems, Web applications, and messaging systems. vSphere also supports well applications with millisecond-level latency constraints, including VoIP services. However, performance demands of latency-sensitive applications with very low latency requirements such as distributed in-memory data management, stock trading, and high-performance computing have long been thought to be incompatible with virtualization.
vSphere 5.5 includes a new feature for setting latency sensitivity in order to support virtual machines with strict latency requirements. This per-VM feature allows virtual machines to exclusively own physical cores, thus avoiding overhead related to CPU scheduling and contention. A recent performance study shows that using this feature combined with pass-through mechanisms such as SR-IOV and DirectPath I/O helps to achieve near-native performance in terms of both response time and jitter.
The paper explains major sources of latency increase due to virtualization in vSphere and presents details of how the latency-sensitivity feature improves performance along with evaluation results of the feature. It also presents some best practices that were concluded from the performance evaluation.
For more information, please read the full paper: Deploying Extremely Latency-Sensitive Applications in VMware vSphere 5.5.