There is no data for thread data for Weblogic 8.1 environments
Weblogic 8.1 JDK version is 1.4.2_06. Any JDK Version 1.4.x has limited collection. This is noted in the installation guide.
There is no work around. Depending on the version/vendor of the 1.4.x. JDK the most it would have collected is information on heap and GC.
The “most” that an agent collects on *any* 1.4.x JDK is heap and GC metrics. Nothing more than that.
Under 1.4.x JDK umbrella, the following is collected for diff. vendors
On 1.5 and 1.6 JDK the agent collects all metrics, with the exception of 1.5 JrockIt that has some issues on some platforms as documented.