To optimize performance, net execs must manage an application throughout its life cycle, from predeployment to the user desktop. The following technologies can help.
Application profiling: Available from companies such as Compuware, Mercury Interactive, NetIQ and Opnet, these software tools help network managers work with application developers by simulating how new or revised applications would run if deployed on an existing or upgraded network. By posing what-if scenarios and exploring various options, network managers and application developers can determine an application's footprint, chattiness and bandwidth needs and prevent an application from running poorly because of the application configuration or because network bandwidth is lacking. The software sits on a dedicated workstation or server.
WAN emulation: These products, from companies such as Apposite Technologies and Shunra, let IT managers test whether the application can withstand the increased performance demands of the wide area. For instance, Shunra's Virtual Enterprise runs transactions over a production network and measures the performance of the application against predefined service-level metrics. The technology also runs network impairments, such as latency, packet loss and utilization, against the application to test its merit against changing network conditions.
With Apposite's WAN emulator, network equipment and applications that would be used on opposite ends of the WAN link are installed on either side of the emulator. Users then configure the bandwidth, latency, packet loss rate, bit error rate and other parameters, and the WAN emulator applies these characteristics to the traffic.
Traffic-flow analysis: Companies such as Network General, Network Physics, NetQoS and NetScout deliver products that help network managers monitor application traffic in real time. Network-management tools that incorporate traffic monitoring, packet capture, bandwidth consumption and protocol analysis can show network managers the path of application packets. The response time at hops along the way remains a critical metric to measure, and IT managers should track such statistics consistently for capacity planning and trend analysis.
Such traffic-analysis tools, which can passively monitor traffic using probes distributed on key servers or strategically throughout a network, also can give network managers a real-time view of performance across IT silos such as servers, storage, databases and the network.
Application discovery and dependency mapping: This technology is becoming the must-have tool for management vendors such as BMC Software, CA, EMC SMARTS, HP, IBM, Mercury and Opsware, and is attracting such newcomers as Cendura, Tideway and nLayers. The idea behind this technology is that network managers can't manage application performance adequately without first knowing what they have and when it's changed.
While the approach - with software or appliances - varies, the technology passively monitors traffic to discover which applications talk to which servers, for instance. Application dependency mapping technology can represent the servers, databases, routers and user machines associated with an application. It also can show whether a problem on one link in the chain will affect service delivery to the user. The data collected by the software also can populate a configuration-management database.
Application acceleration: Gartner breaks down this general category into two product types: application delivery controllers (ADC) and WAN optimization controllers (WOC). ADCs reside in the data center and are deployed asymmetrically, meaning only on the data center end (much like Cisco's recent Application Control Engine release), Gartner says. ADCs can accelerate user performance of browser-based and related applications by providing several technologies that work at the network and applications layers. On the other hand, WOC products are deployed symmetrically on either end of a WAN link and improve the performance of applications accessed across the WAN. The technologies typically address bandwidth consumption, latency and protocol issues.
Besides Cisco, companies offering products in this category include Blue Coat Systems, Citrix Systems, Expand Networks, F5 Networks, Juniper Networks, Orbital Data, Packeteer, Riverbed, Silver Peak Systems and Stratacache.
Client-side performance monitoring: Determining user experience is not a new technology area. Adlex, BMC, Coradiant, CA, HP, IBM and Ipsum offer tools to measure application performance for users by tracking real traffic. For real user traffic testing, measurement tools often use appliances or software probes to monitor passively all client and data center interactions by attaching to a mirror port on the edge router in a data center. Synthetic Web application and site-performance measurement tests from Keynote and Gomez use agents distributed throughout the Internet to determine how a Web site and the applications running on it react to peak loads and various geographies.
An innovative approach to making sure users are getting peak application performance, industry watchers suggest, could be to install agents on desktops and laptops to capture application performance by the real-world user. Companies such as Reflectent (recently acquired by Citrix) use server and distributed agent software that collect real-time, user-level performance data on the client machine. The software measures the actual experience of a user with the application, a metric that has been challenging to capture.