I have encountered this Beryllium bug when trying to figure out a port collision (which later turned-out to be VPNSERVICE-64).

I have opened integration/distribution features-test [0] and started to do feature:install features listed within odl-integration-compatible-with-all and odl-integration-all one by one. It got progressively slower.
Even with heap increased to 10GB (and using Java 8), the installation of all features did not finish over whole weekend.

There is possibly a memory leak in some part of config subsystem (or less probably the Karaf itself). There is no csit test for this, but it may be created later.
I have seen nothing suspiscious in karaf.log, when compared to direct install of odl-integration-all.

[0] https://git.opendaylight.org/gerrit/gitweb?p=integration/distribution.git;a=blob;f=features-test/src/main/resources/features.xml;h=ec717f1a9a805eb4b2fc252e807e519e1ea986f7;hb=refs/heads/stable/beryllium