Performance Drivers

Some important general factors that affect portal performance and are not release dependent. These factors are the most important factors that should be considered by every customer and portal architect on every deployment.

• Arrival Rates

• User Activity

• Desktop Channel Types

Arrival Rates

Arrival rates are defined as the rate at which portal users (employees/customers) login over a period of time. Arrival rates with steep peaks can cause Portal Server to became CPU-bound even if at other times throughout the day CPU utilization is minimal. Consider the example where, employees and/or customers of an enterprise start connecting to the portal early in the morning, remain mostly idle for rest of day and either logout due to session time out or manually logout at end of business. This is the most common scenario for business to employee portals and for some outward-facing portals with high locality of their user base. The rate at which the users login in the morning or logout at the end of day and perform any interaction with the portal server, determines the throughput demanded from the portal server. The throughput test gives a reliable conclusion for this requirement.

User Activity

User activity is defined as the interaction that a portal users has with the portal server. It depends on the number of tabs, links, sites that a user has to go through to reach a specific channel or information.

User activity is also governed by the type of channels that a portal architect may decide to provide the users. For example, if the communications channels (default Mail and Calendar channels shipped with the Portal server software) are placed on a user's portal desktop, the user tends to demand updated content regularly. Such Portal sites with communication channels or connections to back-end systems face far shorter reload intervals . The affect of reloading the desktop is that it consumes CPU cycles and generates jvm heap garbage. Because portal is good at caching, sites that promote reloads can become memory bound before the CPU is stressed. It is recommended to use the JVM option for Concurrent garbage collector to alleviate this issue.

Desktop Channel Types

Configuration of the portal desktop can make a difference in portal server performance. While designing a portal desktop, the baseline data should be referenced as a starting point to guide through the desktop design process. A feature rich desktop is good to entice users to your portal, but you should consider the portal response time for an overall user experience. It is necessary to keep the desktop within a defined performance envelope. Types of channels used on the desktop make a huge difference. Some channels are considered cheap and others categorized as expensive . Cheap channels are the ones that when added do not affect performance and in contrast adding expensive channels will show some performance degradation. In general, the expensive channels are those that require a back-end service or are computationally expensive. It is generally advised to use connection pooling mechanisms for these. Adding a URL scrapper channel to the desktop generally shows almost no impact on throughput.