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The "SSSP" page has been changed by thomasjungblut: http://wiki.apache.org/hama/SSSP?action=diff&rev1=11&rev2=12 * The SSSP (abbr. for Single Source Shortest Paths) algorithm described in the [[http://people.apache.org/~edwardyoon/documents/pregel.pdf|Google Pregel paper]] was used. * Introduces IO usage, partitioning based on hashing of vertextID, and collective communication. - * The implementation for the SSSP can be found at [[https://svn.apache.org/repos/asf/incubator/hama/branches/0.4/examples/src/main/java/org/apache/hama/examples/ShortestPaths.java|ShortestPath]]. == Short summary of the algorithm == @@ -19, +18 @@ == Usage == {{{ - bin/hama jar ../hama-0.4.0-examples.jar sssp <start vertex> <input path> <output path> [number of tasks] + bin/hama jar ../hama-0.x.0-examples.jar sssp <start vertex> <input path> <output path> [number of tasks] }}} You need to provide a start vertex name from where the computation should start calculating the shortest paths, scroll down how to provide an input file for it. @@ -42, +41 @@ Make sure that every vertex's outlink can somewhere be found in the file as a key-site. Otherwise it will result in weird NullPointerExceptions. - Now you need to transform the text file using: - {{{ - bin/hama jar ../hama-0.4.0-examples.jar sssp-text2seq /tmp/input.txt /tmp/out/ - }}} - Then you can run sssp on it with: {{{ - bin/hama jar ../hama-0.4.0-examples.jar sssp Berlin /tmp/out /tmp/sssp-output + bin/hama jar ../hama-0.x.0-examples.jar sssp Berlin /tmp/input.txt /tmp/sssp-output }}} Note that based on what you have configured, the paths may be in HDFS or on local disk. @@ -69, +63 @@ }}} On the left side you see your vertex name and on the right the cost which is needed to get to that vertex. - In the output sequence file you should get a org.apache.hadoop.io.Text (KEY) and org.apache.hadoop.io.IntWritable (VALUE) pair which is exactly the output from above.
