Breaking change to our ReplicationEndpoint and BaseReplicationEndpoint.
ReplicationEndpoint implemented Guava 0.12 Service. An abstract
subclass, BaseReplicationEndpoint, provided default implementations
and facility, among other things, by extending Guava
AbstractService class.
Both of these HBase classes were marked LimitedPrivate for
REPLICATION so these classes were semi-public and made it so
Guava 0.12 was part of our API.
Having Guava in our API was a mistake. It anchors us and the
implementation of the Interface to Guava 0.12. This is untenable
given Guava changes and that the Service Interface in particular
has had extensive revamp and improvement done. We can't hold to
the Guava Interface. It changed. We can't stay on Guava 0.12;
implementors and others on our CLASSPATH won't abide being stuck
on an old Guava.
So this class makes breaking changes. The unhitching of our Interface
from Guava could only be done in a breaking manner. It undoes the
LimitedPrivate on BaseReplicationEndpoint while keeping it for the RE
Interface. It means consumers will have to copy/paste the
AbstractService-based BRE into their own codebase also supplying their
own Guava; HBase no longer 'supplies' this (our Guava usage has
been internalized, relocated).
This patch then adds into RE the basic methods RE needs of the old
Guava Service rather than return a Service to start/stop only to go
back to the RE instance to do actual work. A few method names had to
be changed so could make implementations with Guava Service internally
and not have RE method names and types clash). Semantics remained the
same otherwise. For example startAsync and stopAsync in Guava are start
and stop in RE.
ec7bca1769