5 reasons to avoid agents for application performance management

This vendor-written tech primer has been edited by Network World to eliminate product promotion, nevertheless readers should note it will likely favor the submitter's approach.

Certainly, this practice can yield useful information for managing application performance, including memory usage and the frequency and duration of function calls. Nevertheless, this legacy APM approach suffers from five inherent drawbacks that make it increasingly untenable in today's IT environments.

* System and network overhead. APM vendors that rely on host-based data gathering claim that their approach imposes "minimal overhead" or "low overhead" on system performance, but these vendors seldom offer guarantees. During the actual overhead incurred depends on the specificity of the data gathered and the application itself, less than 5% performance overhead is an optimistic general estimate.

Five percent overhead might be acceptable for some applications, however the problem is compounded when organizations use multiple monitoring tools, each with their own agent consuming system resources. Should the contingency arise, host-based data gathering consumes bandwidth, creates significant noise on the network as data is sent to a central server and can perturb the very system being monitored.

* Limited visibility of network performance. A strictly host-based view of application performance can provide only secondary indicators of network performance issues that affect application delivery. To compensate, most APM tools that rely on host-based data as well offer a separate network-monitoring component.

Recent gains in processing power and storage capacity have made a network-based APM approach feasible that can perform deep, real-time analysis of application transactions as they pass over the wire. By reassembling application transactions from network traffic and analyzing the application details contained at Layer 7, network-based APM can provide IT teams with valuable insights into application performance, just as a particularly slow database procedure, a specific web server error, or a method used in a transaction.

In addition, this approach extracts valuable network performance metrics from Layer 2 through Layer 4, providing industry-leading TCP analysis and other network-level information.

The time to reassess old assumptions

Now is the time to reassess old assumptions. Already-pressed IT teams cannot afford to deal with the headaches associated with host-based instrumentation any longer. IT organizations owe it to themselves to consider new approaches to managing their application performance. Network-based APM offers an elegantly simple alternative that delivers comprehensive health and performance data during completely avoiding problems inherent to gathering host-based performance data.

ExtraHop Networks is a leading provider of network-based application performance management solutions. The ExtraHop Application Delivery Assurance system performs the fastest and deepest analysis in the industry, achieving real-time transaction monitoring at speeds up to a sustained 10Gbps in a single appliance and application-level visibility with no agents, configuration, or overhead. For more information, visit www.extrahop.com.