org.apache.maven.plugin.MojoExecutionException: protoc failure

Question

I meet some problems when i use maven to complie hadoop from source code.Here is the error, can anyone help me? Thanks.

[ERROR] Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:3.0.0-SNAPSHOT:protoc (compile-protoc) on project hadoop-c
 [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.apache.hadoop:hadoop-maven-plugins:3.0.0-SNAP
plugin.MojoExecutionException: protoc failure
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:217)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
        at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
        at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156)
        at org.apache.maven.cli.MavenCli.execute(MavenCli.java:537)
        at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:196)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:141)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
        at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
        at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:409)
        at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:352)
Caused by: org.apache.maven.plugin.MojoExecutionException: org.apache.maven.plugin.MojoExecutionException: protoc failure
        at org.apache.hadoop.maven.plugin.protoc.ProtocMojo.execute(ProtocMojo.java:81)
        at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101)
        at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209)
        ... 19 more
**Caused by: org.apache.maven.plugin.MojoExecutionException: protoc failure**
        at org.apache.hadoop.maven.plugin.protoc.ProtocMojo.execute(ProtocMojo.java:78)
        ... 21 more
[ERROR]
[ERROR]

Answer 1

The instructions at http://wiki.apache.org/hadoop/HowToContribute explain some of the less obvious aspects of building hadoop - including this one. The main problem here is that Protocol Buffers are required by hadoop's YARN framework, and you most likely do not have them installed.

It seems like the problem might be that your not interpretting the error correctly, so --

How to Isolate the Build error

Any mojo which fails should be associated with a class.

In this case, the mojo that is failing is here :

https://svn.apache.org/repos/asf/hadoop/common/trunk/hadoop-maven-plugins/src/main/java/org/apache/hadoop/maven/plugin/protoc/ProtocMojo.java

Looking at the code, its clear that this Mojo requires the "protoc" program to run.

http://code.google.com/p/protobuf/

Solution

To build hadoop, you need protocol buffers. This can be installed on a *NIX machine from source, by running the following commands to grab the code from googlecode (taken from http://numbers.brighterplanet.com/2012/04/14/how-to-install-mosh-on-amazon-ec2/).

wget http://protobuf.googlecode.com/files/protobuf-2.4.1.tar.gz
tar xzf protobuf-2.4.1.tar.gz
cd protobuf-2.4.1
./configure
make
sudo make install
sudo ldconfig