Hi joe, you get this error when one of the component mapreduce jobs dies. Try going to the job tracker and seeing if there are failed jobs -- you'll be able to get the logs of individual tasks that might contain the actual error.
On Feb 21, 2012, at 3:21 PM, Joe Gutierrez <[email protected]> wrote: > Hi all, > > I am trying to run one of the examples from the pig 0.9.2 distribution and > am running into the following exception: > > > [junit] Unable to open iterator for alias queries_limit > [junit] org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: > Unable to open iterator for alias queries_limit > [junit] at org.apache.pig.PigServer.openIterator(PigServer.java:901) > [junit] at org.apache.pig.pigunit.PigTest.getAlias(PigTest.java:183) > [junit] at TopQueriesTest.testTop2Queries(TopQueriesTest.java:32) > [junit] Caused by: java.io.IOException: Couldn't retrieve job. > [junit] at org.apache.pig.PigServer.store(PigServer.java:965) > [junit] at org.apache.pig.PigServer.openIterator(PigServer.java:876) > > Below is my pig script: > > data = LOAD '$input' AS (query:CHARARRAY, count:INT); > queries_group = GROUP data BY query; > queries_sum = FOREACH queries_group GENERATE group AS query, > SUM(data.count) AS count; > queries_ordered = ORDER queries_sum BY count DESC; > queries_limit = LIMIT queries_ordered $limit_count; > STORE queries_limit INTO '$output'; > > and below is my input data: > > yahoo 10 > twitter 7 > facebook 10 > yahoo 15 > facebook 5 > > I've included my pig unit code as well: > > public void testQueries() > { > String[] args = { > "limit_count=3", > "input=<path_to_input_file>", > "output=<path_to_output_file>", > }; > > test = new PigTest(<path_to_pig_script>, args); > > String[] output = { > "(yahoo,25)", > "(facebook,15)", > "(twitter,7)", > }; > > test.assertOutput("queries_limit", output); > > } > > When I execute the test, I receive the exception above. When I alter the > unit test to assert on queries_sum, I receive the correct values. However, > when I assert on queries_ordered or queries_limit, I receive the exception. > How do I resolve this issue? Thanks in advance. > > -- > Joe Gutierrez :: Software Developer
