Web Server Web servers are by far the least common source of performance bottlenecks, though they can cause problems when collecting content from multiple separate servers or when they're used to process business logic. While tuning and optimization can help, Web server bottlenecks are perhaps the only type of performance problem in which adding additional hardware is often the best solution. From a processing perspective, app servers do the bulk of the heavy lifting in a well-designed Web site, and it is therefore not surprising that they are often a veritable breeding ground for performance bottlenecks of every size and description. The bad news is that server tuning is something of a black art. Problems with application components are less common, as they are often discovered in functional testing or early in the testing process.
Difficulties also can arise in the interaction between the app server and database server.
Because the app server acts as a gateway for queries to the database, small communications errors between the two can produce a large obstacle for traffic. Database Database servers are particularly vulnerable to stress because, unlike Web application servers, their functionality is often difficult to distribute across more than one machine. Though they are typically shielded from the brunt of the Web site's load, an imperfectly optimized database server can easily be swamped by queries from a bank of app servers. All Rights Reserved. Ziff Davis Publishing Holdings Inc. ZDNet and Ziff Davis Media are no longer affiliated with each other.