Hi, some notes

Actual

2017-09-09 00:11:06,177 | INFO | pool-2-thread-1 | xtensionProviderContextActivator | 100 - org.opendaylight.bgpcep.bgp-rib-spi - 0.9.0.SNAPSHOT | Starting 0 RIBExtensionProviderActivator instances

2017-09-09 00:11:49,148 | INFO | pool-2-thread-1 | BGPActivator | 222 - org.opendaylight.bgpcep.bgp-inet - 0.9.0.SNAPSHOT | Starting Inet BGP Activator
2017-09-09 00:11:49,149 | INFO | pool-2-thread-1 | RIBActivator | 222 - org.opendaylight.bgpcep.bgp-inet - 0.9.0.SNAPSHOT | Starting Inet RIB Activator

2017-09-09 00:11:49,610 | INFO | pool-2-thread-1 | BgpDeployerImpl | 228 - org.opendaylight.bgpcep.bgp-rib-impl - 0.9.0.SNAPSHOT | BGP Deployer global-bgp started.

steps

feature:install odl-bgpcep-bgp-rib-api
(wait to complete)
feature:install odl-bgpcep-bgp-rib-impl

=====================================================

Expected

2017-09-09 00:30:55,229 | INFO | pool-2-thread-1 | BGPActivator | 98 - org.opendaylight.bgpcep.bgp-inet - 0.9.0.SNAPSHOT | Starting Inet BGP Activator
2017-09-09 00:30:55,230 | INFO | pool-2-thread-1 | RIBActivator | 98 - org.opendaylight.bgpcep.bgp-inet - 0.9.0.SNAPSHOT | Starting Inet RIB Activator

2017-09-09 00:30:55,247 | INFO | rint Extender: 2 | xtensionProviderContextActivator | 105 - org.opendaylight.bgpcep.bgp-rib-spi - 0.9.0.SNAPSHOT | Starting 1 RIBExtensionProviderActivator instances

2017-09-09 00:31:38,113 | INFO | pool-2-thread-1 | BgpDeployerImpl | 228 - org.opendaylight.bgpcep.bgp-rib-impl - 0.9.0.SNAPSHOT | BGP Deployer global-bgp started.

feature:install odl-bgpcep-bgp-inet
(wait to complete)
feature:install odl-bgpcep-bgp-rib-api
(wait to complete)
feature:install odl-bgpcep-bgp-rib-impl

Conclusion:

Issue here is that SimpleRIBExtensionProviderContext under rib-spi is created and expose RIBExtensionProviderContext service before that any extension is loaded.

Fix should imply that registry is restarted each time a new extension starts, forcing all sessions to restart and support this new extensions

Read https://bugs.opendaylight.org/show_bug.cgi?id=8929