JBDS performance problems if it contains huge number of maven projects

Issue

• JBoss Developer Studio 9.1 installation is used in this scenario to develop and build a large number of Java EE projects. e.g. 17 maven modules, 20,000 Java classes, maven dependencies to many other projects etc. The projects contain many JUnit test classes and it has been seen that while building the projects, updating any of it's project artifacts and even running any of the JUnit test classes causes serious performance issues with JBDS. If developers try to run any of the JUnit tests it runs very slow and the following messages are seen in the console.

[INFO] Copying 1 resource
[INFO] Copying 6 resources
...

This procedure takes up to 3 minutes and the developers have no option but to wait until copying is finished, and they even need to wait further for some activities (which can not be seen or logged on console). Finally the test is executed.

• If developers start the same test again the copying procedure [INFO] Copying 6 resources is gone. But it takes also some time to execute the test. In a smaller project this activity is faster, however in a larger
  project it is slower. Similar issues have been reported here too https://bugs.eclipse.org/bugs/show_bug.cgi?id=481417 . What is JBDS doing behind the scenes which makes it perform so slow and what can be done to execute the JUnit tests faster?