When a release candidate has been cut, a vote is started, inviting all members of the community to test the release candidate before actually declaring it an official release. What/how to test before casting your vote?
Checking the distributables (tar.gz and/or zip files)
Just download the distributables and check their contents:
Building the release candidate from source
Download and unpack the release candidate's source distribution. To test if all dependencies are available and all the necessary Maven repositories have been properly declared, it's best to temporarily move aside (or delete) your local Maven repo:
Afterwards, do a full build as usual, preferably including running all unit tests.
Testing the binary distribution by running the examples
Download and unpack the binary distribution. Try running the examples.