Modeling user behavior in enterprise applications is fairly simple. Most everyone is inputting the same type of data at the same time of day and using the same amount of bandwidth.
Not so for social-networking sites; one user is posting poetry, another is sharing pet photographs and a third is uploading home movies. It's hard to predict what users will do, what services they will demand or even how many there will be at one time. All that makes scaling the application difficult.
"It's very difficult to figure out how you're going to make something like that work [on the technical side], and it's really an unsolved problem," said Elisabeth Boonin, director of engineering for Wallop, a social networking company spun out of Microsoft Research.
To address the scaling problem, Wallop turned to Symphoniq and its TrueView load testing and application performance management software.
Symphoniq has developed technology that injects HTML script into a browser. The browser, in turn, discloses performance information like broken links or error messages and reports back to the Symphoniq server, said Hon Wong, the company's CEO. "We tag along in an unobtrusive manner. There's not change of application logic," Wong noted.
From there, the management server records each transaction and compares it to a pre-determined threshold -- say, a five-second wait for a particular page to load. If the transaction exceeds the threshold, then it is traced back to the database, the server, the method call and whatever else may have slowed it down, Wong said.
"From 30,000 feet to three feet, you know which SQL query is causing the problem, which parameters are causing the problem," Wong said. This way, he added, a developer acting alone can address the situation, instead of calling in a "triage team" that also includes server, network and database professionals.
Using the SQL Server Reporting Service, the transaction data is then stored. Developers can go back and identify the particular end user or server that is being affected, Wong said. Being able to pinpoint which user saw a slowdown is especially important for a social networking site, he said. "In Web 2.0…if a user has to wait a couple seconds, he'll go somewhere else."
Wallop is currently in beta and slated to go live later this year. Boonin said she is confident that TrueView will help Wallop expand rapidly and provide the services its users want. "TrueView is an insider's view to what is happening there, as opposed to custom tracing tools or trial and error," she said. "You can cut down on a huge treasure hunt trying to find the problem."
TrueView is available for .NET, J2EE and Web-based applications. It supports SQL Server, MySQL, Oracle, DB2 and Sybase databases. More information is available here.