This week Jim is at the Interop conference in Vegas where he is moderating ten sessions. In his opening session, entitled Application Delivery 2.0, Jim will discuss why he thinks that the movement to adopt virtualization and cloud computing fundamentally change IT. We will use this newsletter to focus on one small piece of how virtualization changes IT.
This week Jim is at the Interop conference in Vegas where he is moderating 10 sessions. In his opening session, entitled Application Delivery 2.0, Jim will discuss why he thinks that the movement to adopt virtualization and cloud computing fundamentally change IT. We will use this newsletter to focus on one small piece of how virtualization changes IT.
The arithmetic of ADCs
As we have pointed out in previous columns, in the traditional non-virtualized IT environment, when the performance of an n-tier application degrades it is typically noticed first by the end user and not by the IT organization. This fact that in many cases the assumption is made that the source of the degraded application performance is the WAN tends to elongate the amount of time it takes to identify and resolve the problem.
Identifying the source of a performance problem becomes more complex after IT organizations have implemented server virtualization. To put the challenge of troubleshooting on a per-VM basis into perspective, consider a hypothetical four-tier application that will be referred to in this newsletter as BusApp. For the sake of this example, assume that the users of BusApp complain of sporadic poor performance and that BusApp is implemented in a manner such that the web server, the application server and the database server are each running on VMs on separate physical servers.
In order to troubleshoot application performance in this type of an environment, an IT organization needs detailed information on each of the three VMs and the communications between them. In the current environment, the vast majority of IT organizations don’t have that level of visibility. The good news is that as will be explained in some of Jim’s other sessions, technologies are being deployed that can provide IT organizations with that visibility. The bad news is that there are multiple, conflicting approaches to gaining that visibility which unto itself complicates the situation.
For the sake of example, assume that the IT organization has deployed the tools and processes to gather this information and has been able to determine that the reason that BusApp sporadically exhibits poor performance has nothing to do with the WAN. The reason is that the application server occasionally exhibits poor performance. However, just determining that it is the application server that is causing the application to perform badly is not enough. The IT organization also needs to understand why the application server is experiencing sporadic performance problems. The answer to that question might be that other VMs on the same physical server as the application server are sporadically consuming resources needed by the application server and that as a result, the application server occasionally performs poorly. Performing this level of detailed analysis will be a daunting task for most IT organizations.
This is just one example of the added challenges that are created by virtualization and cloud computing. In future newsletters we will talk more about both the challenges and the myriad solutions that are being deployed in order to respond to those challenges.
