Hi Fabrizio, I'm just getting started with Giraph and struggled with getting a 'hello world' example running too. It looks like you're missing the input and output path arguments (-ip, -op) telling Giraph where to load your data from and where to write the results.
If you just want to see something working and don't mind which data you process, I found following along with the shortest path example helpful (https://cwiki.apache.org/confluence/display/GIRAPH/Shortest+Paths+Example). I got the algorithm working through GiraphRunner by loading the sample data from (http://ece.northwestern.edu/~aching/shortestPathsInputGraph.tar.gz) into hadoop at ~/shortestPathsInputGraph and then running the following: hadoop jar giraph-0.2-SNAPSHOT-for-hadoop-0.20.203.0-jar-with-dependencies.jar \ org.apache.giraph.GiraphRunner \ org.apache.giraph.examples.SimpleShortestPathsVertex \ -if org.apache.giraph.io.JsonLongDoubleFloatDoubleVertexInputFormat -ip shortestPathsInputGraph \ -of org.apache.giraph.io.JsonLongDoubleFloatDoubleVertexOutputFormat -op shortestPathsOutputGraph \ -w 1 Hope that helps. Best wishes, Henry On 6 Sep 2012, at 09:00, fabrizio silvestri wrote: > Hello Everybody, > > I'm very new to giraph and I would like to run some toy example before > trying to add my parts of code. In particular I would like to run a > PageRank computation on a toy graph stored on a text file with a > format that is compatible with > org.apache.giraph.io.IntIntNullIntTextInputFormat > > When run with > > hadoop jar giraph-0.2-SNAPSHOT-for-hadoop-0.20.203.0-jar-with-dependencies.jar > org.apache.giraph.GiraphRunner \ > org.apache.giraph.examples.SimplePageRankVertex -w 1 \ > -if org.apache.giraph.io.IntIntNullIntTextInputFormat \ > -of org.apache.giraph.io.IdWithValueTextOutputFormat > > > I got the following error: > > 12/09/06 09:59:24 INFO giraph.GiraphRunner: No input path specified. > Ensure your InputFormat does not require one. > 12/09/06 09:59:24 INFO giraph.GiraphRunner: No output path specified. > Ensure your OutputFormat does not require one. > Exception in thread "main" java.lang.IllegalArgumentException: > checkClassTypes: Vertex index types don't match, vertex - class > org.apache.hadoop.io.LongWritable, vertex input format - class > org.apache.hadoop.io.IntWritable > at > org.apache.giraph.graph.GiraphTypeValidator.verifyVertexInputFormatGenericTypes(GiraphTypeValidator.java:116) > at > org.apache.giraph.graph.GiraphTypeValidator.validateClassTypes(GiraphTypeValidator.java:100) > at org.apache.giraph.GiraphRunner.run(GiraphRunner.java:231) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:65) > at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:79) > at org.apache.giraph.GiraphRunner.main(GiraphRunner.java:247) > 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.apache.hadoop.util.RunJar.main(RunJar.java:156) > > I know this might sound stupid... but... I'm really stuck, here! :) > > Is there any OuputFormat compatible with IntIntNullIntTextInputFormat? > > Thanks in advance > f
