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Time to look at apps within virtualised systems
Taking an application-centric approach
By Vic Nyman, Network World (US)
Published: 12:23 GMT, 12 February 09
In an attack on costs, organisations are virtualising servers that support business-critical applications. While many tools help manage virtual servers, they provide little real-time, actionable data on how the virtualised applications themselves are performing and how they interact with one another and the infrastructure on which they reside.
To ensure transactional business applications are functioning properly in a mixed virtual/physical server set-up, IT managers should therefore take an application-centric approach to management and optimisation, and they can get what they need using Application Service Management (ASM) tools.
With applications abstracted from the physical server hosting the virtual machine (VM), support organisations must be able to determine where an application is bogging down. However, many do not have the visibility necessary to monitor what or how their applications are doing on the VMs. They can measure and report symptoms but cannot diagnose the cause.
The typical siloed approach to problem identification focuses on the VM, the server or the network. This fails to show where the application goes and the shape of its infrastructure (virtual, physical or both), and only provides a fraction of the performance details required for effective problem solving. Because virtualisation breaks the one-to-one relationship of server-to-application, organisations can no longer solely rely on machine performance indicators to determine the health of their applications.
Application dependencies must be mapped and monitored across servers and operating systems throughout the enterprise. With an application-centric approach and the proper ASM tools to visualise interdependencies down to the process level, application owners and IT support teams can keep complex applications performing well. This approach relies on the following application-specific data for effective problem triage and resolution: application structure and dependencies; response times; specific resources used; bytes sent & received; and processes maintained, dropped or stalled.
Only by following the application service level, with insight into health and performance at each hop along the dependency chain, can application support dive into the server stack to determine if there are bad connections, an overloaded VM, server-hosting conflicts or any number of server-related issues.
Consider this example: a company has virtualised much of its data centre and suddenly a user's application has become non-responsive. After two days of work, application support realised a server the application depended on had been converted to a VM, yet the application was still making calls to the original physical machine.
An application-centric ASM approach would have mapped shifting application relationships as they migrated to a virtual infrastructure, allowing support to follow the application, isolate the problem, and save days and thousands of dollars in downtime and diagnostics.
Physical-to-Virtual (P2V) projectsThe application-centric approach also becomes an imperative as dynamic data centres change the shape of the application ecosystem. For example, virtualisation can add a processing strain by offloading network I/O, which goes beyond simply stacking too many VMs on top of a host server. virtualisation causes network I/O - and often storage I/O - to be handled multiple times by the same CPU complex. This generates new CPU overhead directly associated with I/O functions.
As the number of transactions and dependencies involved in that environment grow (such as those associated with n-tier business applications and service-oriented architecture deployments) applications do not scale as simply as one might expect. Applications and infrastructure teams need to do their homework on application I/O to prepare for increased CPU utilization in advance of a P2V conversion. To accomplish this, they need tools that can monitor these issues in real time as their VM environments change.
With an application-centric ASM approach processes can be seen, VM changes can be monitored, and detailed performance data is available for every connection so application visibility is maintained, regardless of the latest data centre change.
Lack of application visibility in virtualised environments has caused some organisations to throw more resources at performance issues, exacerbating the problem. Take a further example: to address application downtime, IT staff at a leading software provider have been delivering more capacity and provisioning more VMs to keep things running. However, they soon over-provisioned their users and wasted resources, which negated the benefits of all their previous virtualisation efforts.
The solution? By using tools that provide visibility into applications as they reside on virtual servers, support teams followed the service level across the infrastructure, drilling into the server stack to isolate problems and eliminate the need for additional resources, ultimately meeting user requirements while optimising their resource pool.
Today, ASM tools are capable of providing access to real application data for virtualised environments versus. modelled data. This gives application owners the confidence to virtualise complex applications, knowing they will perform as expected.
These solutions use intelligent data collectors (a service that runs in the operating systems of a few servers) to passively collect data by monitoring the application request layers. The collector sends detailed statistics on the operating systems by using either Windows Management Instrumentation or ESX Server when connecting to VMware Virtualcentre (recently renamed "vcentre") management APIs. This data helps administrators understand application performance and track its movement in order to detect potential bottlenecks and failures.
ASM tools provide application support and infrastructure owners the visibility required to manage the performance and availability of applications deployed in virtualised data centres. The ASM approach includes three critical elements:
- Application discovery and mapping: Discovery and mapping of application connections, processes and interdependencies, allowing for visibility into both physical and virtual environments.
- Service-level health measurement: Service-level performance intelligence detailing connections, usage and application access times, depicting the relative health of complex applications.
- Triage of application and server problems: Performance indicators highlight areas of concern, showing where to focus efforts to solve problems and optimize the IT environment.
Since ASM stresses a business-centric approach, application support and infrastructure owners can align service-level objectives with overarching business priorities. This application-centric approach helps clarify goals across organisations and improves responsiveness.
As a result, application and infrastructure support can focus on the availability, performance and mutually defined parameters of business processes, as well as specify the processes through service-level agreements. Essentially, ASM gives IT teams a common language to share objectives and provides visibility into application performance and availability, allowing them to control and improve service delivery to the customer.
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EricB | Published: 07:51 GMT, 05 May 2009
Modified white-paper piece tried hard to sound techonology-agnostic up until the restrictive references to VMware and Microsoft as if these are the only such technologies available. Throw up the FUD - then, suggest ONLY Microsoft and VMware as 'solutions'. Perhaps this will work with an ignorant corp finance type reading this, then thinks he knows something in the next meeting at work.