Protobuf 2.5 JAR is no longer needed at runtime.
The option common.protobuf.scope defines whether the protobuf 2.5.0
dependency is marked as provided or not.
* New package org.apache.hadoop.ipc.internal for internal only protobuf classes
...with a ShadedProtobufHelper in there which has shaded protobuf refs
only, so guaranteed not to need protobuf-2.5 on the CP
* All uses of org.apache.hadoop.ipc.ProtobufHelper have
been replaced by uses of org.apache.hadoop.ipc.internal.ShadedProtobufHelper
* The scope of protobuf-2.5 is set by the option common.protobuf2.scope
In this patch is it is still "compile"
* There is explicit reference to it in modules where it may be needed.
* The maven scope of the dependency can be set with the common.protobuf2.scope
option. It can be set to "provided" in a build:
-Dcommon.protobuf2.scope=provided
* Add new ipc(callable) method to catch and convert shaded protobuf
exceptions raised during invocation of the supplied lambda expression
* This is adopted in the code where the migration is not traumatically
over-complex. RouterAdminProtocolTranslatorPB is left alone for this
reason.
Contributed by Steve Loughran
This is a followup to HADOOP-18275 and its upgrade of os-maven-plugin.version
When that change is merged in, this MUST follow it.
Contributed by Steve Loughran
