HADOOP-16620. [pb-upgrade] Remove protocol buffers 3.7.1 from requirements in BUILDING.txt

BUILDING.txt

@@ -6,7 +6,6 @@ Requirements:
 * Unix System
 * JDK 1.8
 * Maven 3.3 or later
-* ProtocolBuffer 3.7.1
 * CMake 3.1 or newer (if compiling native code)
 * Zlib devel (if compiling native code)
 * Cyrus SASL devel (if compiling native code)
@@ -62,16 +61,6 @@ Installing required packages for clean install of Ubuntu 14.04 LTS Desktop:
   $ sudo apt-get -y install maven
 * Native libraries
   $ sudo apt-get -y install build-essential autoconf automake libtool cmake zlib1g-dev pkg-config libssl-dev libsasl2-dev
-* ProtocolBuffer 3.7.1 (required)
-  $ mkdir -p /opt/protobuf-3.7-src \
-        && curl -L -s -S \
-          https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-java-3.7.1.tar.gz \
-          -o /opt/protobuf-3.7.1.tar.gz \
-        && tar xzf /opt/protobuf-3.7.1.tar.gz --strip-components 1 -C /opt/protobuf-3.7-src \
-        && cd /opt/protobuf-3.7-src \
-        && ./configure\
-        && make install \
-        && rm -rf /opt/protobuf-3.7-src
 
 Optional packages:
 
@@ -310,16 +299,6 @@ level once; and then work from the submodule. Keep in mind that SNAPSHOTs
 time out after a while, using the Maven '-nsu' will stop Maven from trying
 to update SNAPSHOTs from external repos.
 
-----------------------------------------------------------------------------------
-Protocol Buffer compiler
-
-The version of Protocol Buffer compiler, protoc, must match the version of the
-protobuf JAR.
-
-If you have multiple versions of protoc in your system, you can set in your
-build shell the HADOOP_PROTOC_PATH environment variable to point to the one you
-want to use for the Hadoop build. If you don't define this environment variable,
-protoc is looked up in the PATH.
 ----------------------------------------------------------------------------------
 Importing projects to eclipse
 
@@ -405,15 +384,6 @@ Installing required dependencies for clean install of macOS 10.14:
 * Install native libraries, only openssl is required to compile native code,
 you may optionally install zlib, lz4, etc.
   $ brew install openssl
-* Protocol Buffers 3.7.1 (required)
-  $ wget https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-java-3.7.1.tar.gz
-  $ mkdir -p protobuf-3.7 && tar zxvf protobuf-java-3.7.1.tar.gz --strip-components 1 -C protobuf-3.7
-  $ cd protobuf-3.7
-  $ ./configure
-  $ make
-  $ make check
-  $ make install
-  $ protoc --version
 
 Note that building Hadoop 3.1.1/3.1.2/3.2.0 native code from source is broken
 on macOS. For 3.1.1/3.1.2, you need to manually backport YARN-8622. For 3.2.0,
@@ -439,7 +409,6 @@ Requirements:
 * Windows System
 * JDK 1.8
 * Maven 3.0 or later
-* ProtocolBuffer 3.7.1
 * CMake 3.1 or newer
 * Visual Studio 2010 Professional or Higher
 * Windows SDK 8.1 (if building CPU rate control for the container executor)

dev-support/docker/Dockerfile

@@ -105,23 +105,6 @@ RUN mkdir -p /opt/cmake \
 ENV CMAKE_HOME /opt/cmake
 ENV PATH "${PATH}:/opt/cmake/bin"
 
-######
-# Install Google Protobuf 3.7.1 (2.6.0 ships with Xenial)
-######
-# hadolint ignore=DL3003
-RUN mkdir -p /opt/protobuf-src \
-    && curl -L -s -S \
-      https://github.com/protocolbuffers/protobuf/releases/download/v3.7.1/protobuf-java-3.7.1.tar.gz \
-      -o /opt/protobuf.tar.gz \
-    && tar xzf /opt/protobuf.tar.gz --strip-components 1 -C /opt/protobuf-src \
-    && cd /opt/protobuf-src \
-    && ./configure --prefix=/opt/protobuf \
-    && make install \
-    && cd /root \
-    && rm -rf /opt/protobuf-src
-ENV PROTOBUF_HOME /opt/protobuf
-ENV PATH "${PATH}:/opt/protobuf/bin"
-
 ######
 # Install Apache Maven 3.3.9 (3.3.9 ships with Xenial)
 ######