zookeeper configs for Giraph 1.0 on Hadoop 2.2.0 - apache-zookeeper

Question

New to stack exchange and Giraph so please overlook mistakes and ask any clarifying questions.
OS: ubuntu 13.10
Hadoop/Yarn: hadoop-2.2.0/ (2-node cluster)
Giraph: 1.0.0 (EDIT: trunk)
I'm getting a NullPointerException (NPE) when I attempt to run the following example:
$ hadoop jar
$GIRAPH_HOME/giraph-examples/target/giraph-examples-1.1.0-SNAPSHOT-for-hadoop-2.2.0-jar-with-dependencies.jar
org.apache.giraph.GiraphRunner
org.apache.giraph.examples.SimpleShortestPathsComputation -vif
org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexInputFormat
-vip /user/hduser/rrdata/tiny_graph.txt -vof org.apache.giraph.io.formats.IdWithValueTextOutputFormat -op
/user/hduser/rrdata/output/tiny_graph.out -w 1
Stack Trace:
Exception in thread "main" java.lang.NullPointerException at
org.apache.giraph.yarn.GiraphYarnClient.checkJobLocalZooKeeperSupported(GiraphYarnClient.java:460)
at
org.apache.giraph.yarn.GiraphYarnClient.run(GiraphYarnClient.java:116)
at org.apache.giraph.GiraphRunner.run(GiraphRunner.java:96) at
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70) at
org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:84) at
org.apache.giraph.GiraphRunner.main(GiraphRunner.java:126) at
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:606) at
org.apache.hadoop.util.RunJar.main(RunJar.java:212)
It seems zookeeper related. I installed zookeeper but not having used it before it seems like the configs are wrong. I've tried -Dgiraph.zkList=hostname:port and related options but get 'Unrecognized option' exception.
Looking for the correct zookeeper settings for this scenarios. I'll post a reply if I figure it out.

Answer 1

This is an example how you can specify -D flags:
hadoop jar giraph-examples-1.1.0-SNAPSHOT-for-hadoop-2.2-jar-with-dependencies.jar org.apache.giraph.GiraphRunner -D giraph.zkList="zkNode.net:2081" org.apache.giraph.examples.SimpleShortestPathsComputation -vif org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexInputFormat -vip /user/rav/giraph/input/tiny_graph.txt -vof org.apache.giraph.io.formats.IdWithValueTextOutputFormat -op /user/rav/giraph/output/shortestpaths -w 1
Btw local zookeeper is not supported in Giraph yet (GiraphYarnClient):
/**
* Check if the job's configuration is for a local run. These can all be
* removed as we expand the functionality of the "pure YARN" Giraph profile.
*/
private void checkJobLocalZooKeeperSupported() {
final boolean isZkExternal = giraphConf.isZookeeperExternal();
final String checkZkList = giraphConf.getZookeeperList();
if (!isZkExternal || checkZkList.isEmpty()) {
throw new IllegalArgumentException("Giraph on YARN does not currently" +
"support Giraph-managed ZK instances: use a standalone ZooKeeper.");
}
}
Unfortunately checkZkList is NULL so you will never see this exception :)

Answer 2

The reason for the NPE is probably the lack of a giraphConf to check for ZK settings. i think this is due to earlier problems in the run. Looks like the examples jar was not supplied using a -yj argument. the jar you run with "hadoop jar" is typically giraph-core itself.
Good luck, please post on the Giraph user list if you have more trouble.