Don't blame the network

by Denise Dubie

April 30, 2001 —

When pharmacists at Walgreens found themselves twiddling their thumbs for close to a minute each time they'd make a simple database request, the company's 12-year-old satellite network became an easy target for blame.

"I used to go to meetings and all the managers would be sitting there with their shotguns cocked, blaming the network," says Joe Rosa, who until recently was Walgreens' network communications engineer/network analyst.

But as it turns out, the network -- which provides connectivity to 3,000 stores -- wasn't really at fault.

Rather, the main problem was the way the company had set up its application, which was delivering information to end users on a per-field basis. In other words, a request for an address would result in the person's first name, last name, street, city and other data being sent separately, with each piece of information taking 1.4 seconds to traverse 2,300 miles along the company's satellite network.

Walgreens came to this conclusion after deploying application profiling software. Such software, while not new, is getting new life as increasingly cost-conscious companies try to get a better handle on application and network performance before investing in big upgrades based on assumptions about dwindling network capacity or older software.

Simulating network conditions

Users of application profiling products, sold by the likes of Compuware, NetIQ, Network Associates and Opnet, say the software is easy to install and lets them analyze how existing applications are running by tapping into router configuration tables, LAN probes and applications themselves. Perhaps more importantly, such software can be used to simulate how new applications would run if deployed on an existing or upgraded network. The software, which can sit on a dedicated workstation, client workstation or server, typically costs between $10,000 and $25,000.

Gartner analyst Bill Gassman calls such programs "blame-shifting software." That's because the software, by determining an application's footprint, chattiness and bandwidth needs, can show that an application is running poorly because of the application itself and not because network bandwidth is lacking or vice versa. Presented with this information, IT staffers are more likely to stop finger-pointing, he says.

According to Gassman, one common problem these tools uncover is that off-the-shelf applications, such as SAP enterprise resource program packages and Microsoft offerings such as Exchange, tend not to be as aware of a company's particular network as the homemade applications many companies previously relied on.

Surprise discovery

LensCrafters is among the companies that have put application profiling software to use and been surprised by the results.

The eyecare company used the software to troubleshoot performance issues with a Decision Support System application used by 225 remote laptop users. It was taking 15 to 50 minutes -- rather than the 10 or fewer minutes it should have taken -- for users to download 2.5M bytes of data from a Sybase Open Client database.

LensCrafters assumed the issue had to do with connection speeds, but Compuware's Application Expert software showed otherwise.

The software helped LensCrafters discover about one-quarter of each 2.5M-byte file downloaded contained static code. The company then adjusted the application so that only changed code would be replicated to remote users. That cut download times by 25%, and the company avoided a needless and expensive bandwidth upgrade.

"Application Expert has really pointed out that you can't just throw bandwidth at a poorly performing application and expect it to work," says Chris Ray, LensCrafters' director of technical services.

Compuware's Application Expert cost LensCrafters about $20,000, and it took Ray and other team members about six hours to get the server software and network probes up and running and collecting data.

"The first four hours we had it plugged in, jaws dropped. We saw all these things happening that we didn't know were happening," says Steve Bosch, lead network architect at LensCrafters.

IBM Global Services has long used application profiling software when working with clients that are rolling out new applications, says Tom Thompson, a network performance consultant.

The company cites an unnamed customer that was embarking on a $20 million project to consolidate data for a customer relationship management application at a central location for its 200 connected sites.

The customer assumed that adding network bandwidth could accommodate such a large application. But when the IBM consultants performed an application analysis, they discovered the client's planned network would have to be increased four times the capacity originally considered. The cost of the network upgrade would have negated the benefits of the new application, even if it ran perfectly. And all indications were that it would have run terribly anyway.

Thompson says many companies never even think to have their network and application teams collaborate on solving such problems.

"One of the advantages of using tools like these, is that they don't have any opinion," he says. "It doesn't matter who gets the credit or blame. They're not out to protect their turf."

Network World