Size Maximum Thread Count

Sizing the bbconfig.appserver.maxthreads parameter is different for every Blackboard Learn deployment because the proper setting depends on application usage.

Before changing this parameter value, make sure to understand system usage needs versus the resource capacity of CPU and Memory because both are factors. A one-to-one correlation between application threads and system users does not exist. Tomcat uses a thread pool to manage a volume of user transactions. Most components in Blackboard Learn make single thread requests, and some transactions require two or more threads. These types of transactions are not multi-threaded, but rather they require multiple independent requests such as a frameset. Thread requests typically occur in less than one second.

Thread consumption is a symptom of a performance issue or degradation. Increasing the thread count will not always solve a performance issue. Performance issues should be diagnosed by identifying bottlenecks at their source.

Blackboard recommends setting the value based on need during peak usage time. Start with a relatively conservative value, such as the default value of 200. Monitor thread usage using operating system tools (such as Windows Task Manager, Prstat, NetStat, or Top) or third-party tools (such as Quest Foglight or Sun™ JConsole), and then increase the thread count in increments of 25 to 50 as threads become saturated or used.

When running on UNIX, make sure that the maximum thread count value is less than the bbconfig.unix.httpd.maxclients parameter value in the bb-config.properties file.