One of the slightly annoying things in Giraph is that you have to manually match your input format to your computation. In your case, PageRankComputation requires LongWritable for vertex ID and DoubleWritable for vertex Data. You may need to hack one of the existing formats slightly.
Thanks, Roman. On Sat, Apr 25, 2015 at 2:58 PM, Kenrick Fernandes <kenrick....@gmail.com> wrote: > Hello, > > Im trying to get Giraph to read the Twitter dataset as input for the > SimplePageRankComputation program. The dataset format looks like this: > 61578010 61147436 > 61578037 61147436 > 61578040 61147436 > (vertex id's, with pairs representing edges) > > When I run the command with > -vif org.apache.giraph.io.formats.IntIntNullTextInputFormat, I get this > error : > java.lang.IllegalArgumentException: checkClassTypes: vertex index types not > assignable, computation - class org.apache.hadoop.io.LongWritable, > VertexInputFormat - class org.apache.hadoop.io.IntWritable > > So I tried running the command with > -vif org.apache.giraph.io.formats.LongLongNullTextInputFormat and I get a > different one: > java.lang.IllegalArgumentException: checkClassTypes: vertex value types not > assignable, computation - class org.apache.hadoop.io.DoubleWritable, > VertexInputFormat - class org.apache.hadoop.io.LongWritable > > I dont understand why the types in the input show up as different formats in > each error. Also, as far as I could tell, there is no input format for > DoubleDouble. Is there a different way to get the graph into Giraph without > having to write custom input code ? Thoughts would be much appreciated. > > ----- > Reference Command: > hadoop jar giraph-examples-1.1.0-for-hadoop-1.1.2-jar-with-dependencies.jar > org.apache.giraph.GiraphRunner > org.apache.giraph.examples.PageRankComputation -vif > org.apache.giraph.io.formats.LongLongNullTextInputFormat -vip > /user/kenrick/twitter/input -op /user/kenrick/twitter/output -w 30 > ----- > > Thanks, > Kenrick
