Lots of APM vendors talk about taking a holistic approach to application performance management, but the latest entry in our Rolling Review, Quest Software's Foglight, delivers. It combines network packet capture data and in-depth analysis using intelligent agents and synthetic transactions to enable APM. The system comprises the Foglight Experience Monitor, or FxM; the Foglight Experience Viewer, or FxV; and a new implementation of the Foglight Server to offer views ranging from business services to those low-level traces only an application developer could love.

Foglight's greatest strength is its ability to collect many types of data and present it in a meaningful way. Thousands of metrics are baselined and processed via the rules engine. Alarms may be generated when thresholds are crossed or rules are created and sent via several methods, including SNMP traps, or collected into dashboards.

Foglight dashboards can be created easily and set to model high-level business and service views that clearly identify issues as they occur. Drill-down capabilities provide access to lower-level stats, useful for troubleshooting. FxV offers user-session replay, click by click, for Web applications. This is incredibly valuable for diagnostics as it illustrates the exact order of events that caused a performance glitch.

All that functionality comes with a price in terms of complexity. Still, though Foglight isn't as plug-and-play as some other tools we've reviewed, in particular those from Indicative and Nimsoft, most IT organizations should be able to deal as long as they have an effective deployment plan. Quest or third-party systems integrators are more than happy to assist you.

The virtually infinite flexibility and vast amount of data collected by various monitors can be overwhelming as well. To help here, Foglight Server uses models to represent services and apps. Models are the key to the system's flexibility and power because they group and assign dependencies to all metrics collected. As in other APM systems, you'll require a pair of hands and some knowledge to choose the applications and services that will be modeled, then break them down into component pieces. Applicable metrics are identified along with their dependencies as each model is built. Knowledge of each component is essential, but many of the cartridges include default metrics and thresholds as a starting point.

Given the depth of metrics collected, implementation of models is easier with Foglight than in most products we've seen.

THE GREAT AGENT DEBATE

For deep application performance monitoring, there's no getting around it: Agents are critical. We've found that products with agents provide more detailed and in-depth statistics on application-level processes and data, all crucial in diagnosing app problems.

Quest's Foglight Cartridges are deployable, application-specific units that include monitoring agents, metrics, database modification scripts, and rules--all the components for monitoring vital apps or databases. A variety of Cartridges is loaded by default, and Foglight supports most leading business apps. Note that some Foglight 4.x Cartridges, including those for IIS and ASP/.Net, haven't been ported to the new version 5 architecture. The ASP/.Net Cartridge is scheduled for release by year's end, and the IIS Cartridge is due in the first quarter.

Configuration of agents can be assigned via templates, so it's fairly easy to manage a collection of agents. It would be nice to see more grouping and group functions, rather than an agent-by-agent approach. However, much of the configuration can be done via a command-line utility, which is useful for performing repetitive tasks.

While many organizations cringe at installing and maintaining more agents, they're a necessity for true, application-specific data, and Quest's approach is a reasonable one.

Still, if you can't bring yourself to add one more agent, Quest can provide visibility into critical apps anyway, albeit without as much depth. Synthetic transactions are created using a Recorder that's a wrapper around an Internet Explorer browser object; this makes their creation easier, and being able to tweak each step of the transaction enables simple troubleshooting.

In addition, Quest offers an appliance that focuses on the collection of application packets across the network. The appliance deployment was straightforward and involved configuring the network settings in a typical Linux text menu. Integrating appliance configuration into the Foglight Server is on the product road map, and it will eliminate today's piecemeal approach.