The VMware Knowledge Base provides support solutions, error messages and troubleshooting guides
Performance Issue (for VI SDK 2.0) with JDK Versions Prior to JDK 1.5.0_08 (2983901)
Using the VI SDK 2.0 with JDK versions prior to Java 2, Standard Edition 5 (J2SE5)—specifically, prior to JDK 1.5.0_08—results in poor performance.
The solution is to use Java version 1.5.0_08 (or subsequent version).
Using previous versions of the JDK with VMware Infrastructure API 2.0 can result in operations that seem to "hang" for four-to-five seconds before completing. The reason is that socket creation (new Socket("ip-address", port) ) with JDK (prior to 1.5.0_08) is extremely slow. Creating multiple sockets sequentially (not in parallel) results in an overall cumulative slowdown.
See the Sun Developer Network bug database for information about bug 5092063, which may be the cause of the slow performance:
Request a Product Feature
To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.