Accurately Locate the Problems in the Virtual Data Center

VDC is a new form of data center that applies the concept of cloud computing to the data center. VDC can abstract and integrate physical resources through virtualization technology, dynamically allocate and schedule resources, realize automatic deployment of the data center, and greatly reduce the operating cost of the data center. At present, virtualization plays an increasingly important role in the development of data centers. The concept of virtualization has been extended to desktop, unified communication and other fields, not only including the virtualization of traditional servers and networks. It also includes IO virtualization, desktop virtualization, unified communication virtualization, and so on. VDC is the ultimate realization of virtualization technology in the data center. In the future, virtualization technology will be ubiquitous in the data center. When the data center is fully virtualized, then the data center can be called VDC. VDC will integrate all hardware (including servers, storage and networks) into a single logical resource, so as to improve the efficiency and flexibility of the system, as well as the availability and scalability of application software.

Before virtualization, it is relatively simple to diagnose the application problems on the physical server. In most cases, the administrator can solve the problem by re-configuring, upgrading, or patching the server.

Unfortunately, virtualization diagnostics add a new and complex virtualization layer to application performance. Running multiple workloads is certainly beneficial to improving server utilization, but hardware resource sharing may sometimes lead to unpredictable results and adversely affect workload performance in unexpected ways.

For example, suppose a database server and a multimedia server share the same host server. The server has enough resources to meet the demands of the workload on resources, and in the normal use mode, both workloads deliver sufficient performance.

Now, assuming that users have been complaining about the low performance of database queries, IT professionals usually respond to users' complaints by checking the database server virtual machine, hoping to find that the configuration has changed or the resources are insufficient. But after checking the database server, it seems that the only problem is that when the database query performance is low, the local disk I/O is too frequent, but the frequent local disk activity has nothing to do with the database virtual machine. However, another technician found that the multimedia server virtual machine was processing a large number of video processing requests when the database response was slow.

Even though the database server virtual machine is facing performance problems, this is caused by the local multimedia virtual machine processing a large number of requests. Therefore, the performance of one virtual machine may adversely affect other local virtual machines.

Virtualization may make it complicated to trace the root cause of the problem, because the resources of virtual machines may be adjusted or migrated without considering other load conditions on a specific system. In order to diagnose the above problems more efficiently, IT professionals need to use business service management tools that can identify the physical paths of virtual machines and the applications running on each virtual machine.