Finally I've found the answer in CassandraStorage.java ! columns is not an alias but a bag that you fill with columns (name+value) that don't have metadata.
That's why your sample doesn't return anything in my test as I've only filled existing columns (found in the CQL CREATE command) I think you should update the file cassandra/examples/pig/README.txt to explain where this columns comes from or by changing the description of the test cause it doesn't really determine the top 50 column names but only the top 50 column names put in the bag "columns" (without metadata) Regards -- Cyril SCETBON On Mar 13, 2013, at 6:44 PM, cscetbon....@orange.com<mailto:cscetbon....@orange.com> wrote: I'm trying to execute your sample pig script and I don't understand where the alias "columns" comes from : grunt> rows = LOAD 'cassandra://MyKeyspace/MyColumnFamily' USING CassandraStorage(); grunt> cols = FOREACH rows GENERATE flatten(columns); I suppose it's defined by the call to getSchema function in src/java/org/apache/cassandra/hadoop/pig/CassandraStorage.java however even if the order is well executed by Pig, cols can't be dumped. if I dump rows I get : (iza,(),(),(),(birth_year,77),(gender,F),{}) (cyril,(),(),(),(birth_year,79),(gender,M),{}) but when I dump cols I get nothing :( any idea ? -- Cyril SCETBON On Mar 13, 2013, at 10:26 AM, Cyril Scetbon <cscetbon....@orange.com<mailto:cscetbon....@orange.com>> wrote: Ok forget it. It was a mix of mistakes like environment variables not set, package name not added in the script and libraries not found. Regards -- Cyril SCETBON On Mar 12, 2013, at 10:43 AM, cscetbon....@orange.com<mailto:cscetbon....@orange.com> wrote: I'm already using Cassandra 1.2.2 with only one line to test the cassandra access : rows = LOAD 'cassandra://twissandra/users' USING org.apache.cassandra.hadoop.pig.CassandraStorage(); extracted from the sample script provided in the sources -- Cyril SCETBON On Mar 12, 2013, at 6:57 AM, aaron morton <aa...@thelastpickle.com<mailto:aa...@thelastpickle.com>> wrote: any idea why the function loadFunc does not work correctly ? No sorry. Not sure why you are linking to the CQL info or what Pig script / config you are running. Did you follow the example in the examples/pig in the source distribution ? Also please use at least cassandra 1.1. Cheers ----------------- Aaron Morton Freelance Cassandra Consultant New Zealand @aaronmorton http://www.thelastpickle.com<http://www.thelastpickle.com/> On 11/03/2013, at 9:39 AM, cscetbon....@orange.com<mailto:cscetbon....@orange.com> wrote: You said all versions. However, when I try to access cassandra://twissandra/users based on http://www.datastax.com/docs/1.0/dml/using_cql I get : 2013-03-11 17:35:48,444 [main] INFO org.apache.pig.Main - Apache Pig version 0.11.0 (r1446324) compiled Feb 14 2013, 16:40:57 2013-03-11 17:35:48,445 [main] INFO org.apache.pig.Main - Logging error messages to: /Users/cyril/pig_1363019748442.log 2013-03-11 17:35:48.583 java[13809:1203] Unable to load realm info from SCDynamicStore 2013-03-11 17:35:48,750 [main] INFO org.apache.pig.impl.util.Utils - Default bootup file /Users/cyril/.pigbootup not found 2013-03-11 17:35:48,831 [main] INFO org.apache.pig.backend.hadoop.executionengine.HExecutionEngine - Connecting to hadoop file system at: file:///<file:////> 2013-03-11 17:35:49,235 [main] ERROR org.apache.pig.tools.grunt.Grunt - ERROR 2245: Cannot get schema from loadFunc org.apache.cassandra.hadoop.pig.CassandraStorage with pig 0.11.0 any idea why the function loadFunc does not work correctly ? thanks -- Cyril SCETBON On Jan 18, 2013, at 7:00 PM, aaron morton <aa...@thelastpickle.com<mailto:aa...@thelastpickle.com>> wrote: Silly question -- but does hive/pig hadoop etc work with cassandra 1.1.8? Or only with 1.2? all versions. We are using astyanax library, which seems to fail horribly on 1.2, How does it fail ? If you think you have a bug post it at https://github.com/Netflix/astyanax Cheers ----------------- Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com<http://www.thelastpickle.com/> On 18/01/2013, at 7:48 AM, James Lyons <james.ly...@gmail.com<mailto:james.ly...@gmail.com>> wrote: Silly question -- but does hive/pig hadoop etc work with cassandra 1.1.8? Or only with 1.2? We are using astyanax library, which seems to fail horribly on 1.2, so we're still on 1.1.8. But we're just starting out with this and i'm still debating between cassandra and hbase. So I just want to know if there is a limitation here or not, as I have no idea when 1.2 support will exist in astyanax. That said, are there other java (scala) libraries that people use to connect to cassandra that support 1.2? -James- On Thu, Jan 17, 2013 at 8:30 AM, <cscetbon....@orange.com<mailto:cscetbon....@orange.com>> wrote: Ok, I understand that I need to manage both cassandra and hadoop components and that pig will use hadoop components to launch its tasks which will use Cassandra as the Storage engine. Thanks -- Cyril SCETBON On Jan 17, 2013, at 4:03 PM, James Schappet <jschap...@gmail.com<mailto:jschap...@gmail.com>> wrote: This really depends on how you design your Hadoop Cluster. The testing I have done, had Hadoop and Cassandra Nodes collocated on the same hosts. Remember that Pig code runs inside of your hadoop cluster, and connects to Cassandra as the Database engine. I have not done any testing with Hive, so someone else will have to answer that question. From: <cscetbon....@orange.com<mailto:cscetbon....@orange.com>> Reply-To: <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Date: Thursday, January 17, 2013 8:58 AM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Subject: Re: Pig / Map Reduce on Cassandra Jimmy, I understand that CFS can replace HDFS for those who use Hadoop. I just want to use pig and hive on cassandra. I know that pig samples are provided and work now with cassandra natively (they are part of the core). However, does it mean that the process will be spread over nodes with number_of_mapper=number_of_nodes or something like that ? Can Hive connect to Cassandra 1.2 easily too ? -- Cyril Scetbon On Jan 17, 2013, at 2:42 PM, James Schappet <jschap...@gmail.com<mailto:jschap...@gmail.com>> wrote: CFS is Cassandra File System: http://www.datastax.com/dev/blog/cassandra-file-system-design But you don't need CFS to connect from PIG to Cassandra. The latest versions of Cassandra Source ship with examples of connecting from pig to cassandra. apache-cassandra-1.2.0-src/examples/pig -- http://www.apache.org/dyn/closer.cgi?path=/cassandra/1.2.0/apache-cassandra-1.2.0-src.tar.gz --Jimmy From: <cscetbon....@orange.com<mailto:cscetbon....@orange.com>> Reply-To: <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Date: Thursday, January 17, 2013 6:35 AM To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" <user@cassandra.apache.org<mailto:user@cassandra.apache.org>> Subject: Re: Pig / Map Reduce on Cassandra what do you mean ? it's not needed by Pig or Hive to access Cassandra data. Regards On Jan 16, 2013, at 11:14 PM, Brandon Williams <dri...@gmail.com<mailto:dri...@gmail.com>> wrote: You won't get CFS, but it's not a hard requirement, either. _________________________________________________________________________________________________________________________ Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration, France Telecom - Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci. This message and its attachments may contain confidential or privileged information that may be protected by law; they should not be distributed, used or copied without authorisation. 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