Hi, I was trying to run the giraph simple shortest path example (that comes with giraph package) on 3 nodes (1 namenode and 2 datanodes) hadoop-0.23.10 cluster. I used 7 mappers and 7 reducers run simultaneously at each node in mapred-site.xml.
The command I typed: $HADOOP_HOME/bin/hadoop jar /usr/local/giraph-1.1.0/giraph-examples/target/giraph-examples-1.1.0-SNAPSHOT-for-hadoop-0.23.1-jar-with-dependencies.jar org.apache.giraph.GiraphRunner org.apache.giraph.examples.SimpleShortestPathsComputation -vif org.apache.giraph.io.formats.JsonLongDoubleFloatDoubleVertexInputFormat -vip /user/hduser/input/tiny_graph.txt -of org.apache.giraph.io.formats.IdWithValueTextOutputFormat -op /output/shortestpaths *-w 12* When I ran with 12 workers (-w 12) the error was : 'Exception in thread "main" java.lang.IllegalArgumentException: checkLocalJobRunnerConfiguration: When using LocalJobRunner, must have only one worker since only 1 task at a time!' When I change it to 1 (-w 1) the error was: 'Exception in thread "main" java.lang.IllegalArgumentException: checkLocalJobRunnerConfiguration: When using LocalJobRunner, you cannot run in split master / worker mode since there is only 1 task at a time!' What am I missing? -- Thanks and regards, Arghya Kusum Das (225-362-4031)